Ref 1675/8
Source: acollectedman.com
An early example of reference 1675/8 featuring the rare, straight batten hands and the original rivet Oyster bracelet.
Created April 2021, MORNINGTUNDRA

Collectors of the GMT-Master are some of the nerdiest and detail-obsessed of all vintage Rolex enthusiasts. Many subtle design variations were introduced over the years, making this reference enjoyable to learn about but challenging to collect. This is a heady mix for collectors, and the solid gold editions are holy-grail additions to their collections

The GMT-Master is an undeniably cool watch. Its image is associated with a golden era of international travel and adventure. Vintage examples in precious metals are romantic, nostalgic heirlooms, stores of wealth, and sources of great pride for many owners. Many of whom come to find one is simply not enough!

The solid gold GMT-Master debuted in 1954, with reference 6542, the first GMT. This is an extremely rare reference, and in solid gold even more so. The gold 6542/8 is beyond all but the most elite collectors and while they occasionally appear at auction, they are more likely to change hands privately (for the cost a modest family home).

The 6542/8 was followed by the slightly more common solid gold 1675/8 in 1960. These can be more easily found, and for more reasonable money (for the cost of a modest family car).

The 1960's was an exciting time, and Rolex advertising rode the economic, technological, and cultural tide to boost visibility of the GMT-Master. The solid gold GMT-Master sold well, against the gold Submariner, benefiting from advertising associations with pilots of the 747 and Concord.

Vintage GMT-Master vs Submariner
1675/8 vs 1680/8. Both examples from 1977 feature gold nipple dials, applied Rolex coronets, gilt text and minute track, and acrylic crystals. These characteristics are unique to the era and much loved by collectors.

It is a curious fact that prices for solid gold vintage GMT's are generally lower than those of the solid gold Submariner of the same era. The GMT-Master is a more advanced timepiece, with its fourth hand and 24-hour complication. It has a slimmer case profile and wears more comfortably on most wrists. It was offered on more bracelet options (plus leather) and was more aggressively advertised. There is a solid argument for it being the sexier watch on all fronts; and yet the gold Submariner commands a price premium.

Either the Sub is over valued or the GMT-Master is undervalued, offering a better buying and investment opportunity.

Throughout the 1960's and 70's the gold GMT-Master appears to have been a bigger commercial success, outselling the gold Sub. To what extent, nobody knows for sure but examples offered for sale online consistently outnumber the Sub by a modest margin (when comparing references of similar age).

At the time of writing, Chrono24 is offering 40 examples of the 1675/8 versus 26 examples of the equivalent Submariner 1680/8. While not authoritative, this imbalance is representative of what can be found on most watch forums.

Many collectors of vintage watches of this era, agree the gold GMT-Master is a classier, more sophisticated, and versatile choice than the bruiser that is the gold Submariner. Some of this has to do with comfort and wearability (slimmer cases and Jubilee bracelets). Some of it has to do with black and brown dials being more versatile than blue and purple (or even orange).

This article will help you understand the subtle details that make the solid gold GMT so desirable, and will equip you with what you need to know to buy a vintage one.

Ad featuring Concord and the 6542

A 1960s advertisement featuring a 1675/8 with straight batten hands inherited from the earlier 6542/8.

Ad featuring the 747 and the 6542

A mid-60's ad featuring pilots and cockpit of a Boeing 747. Advertised RRP US$1,125!

Ad featuring a 747 and a 1675

A 1970's ad showing a later 1675/8 with Mercedes hands.

An Australian ad featuring a 16718

An Australian 1990's ad featuring a modern-classic 16718.

Lets Talk Gold Content

Made of 18 karat gold, the GMT-Master is 75% pure gold. The remaining 25% is a combination of silver, copper, platinum or palladium (depending on the reference). These additional precious metals were added to form a tougher, more durable gold alloy and the exact composition of the gold alloy has evolved over the half century. Today Rolex operates its own foundry and invests heavily in developing proprietary alloys.

The early vintage GMT-Master cases were made by partners like Genex SA, the case-making department of Gay Frères, the famed bracelet maker. Winding crowns were made by Boninchi and both case and crown would have been hand-finished by Virex et Joli Poli. These companies were acquired in the late 1990's while Patrick Heiniger was at the helm of Rolex.

The exact weight of a gold GMT-Master varies slightly between references, as dimensions and design details evolved. The gold components include the Oyster mid-case, caseback, winding crown, bezel ring, hands, dial markers, spring bars, bracelet and clasp. The weight of these parts is approximately 185 grams.

So, 185 grams x 75% = 138.75 grams of pure gold.

At the time of writing, the spot price of gold is about US$57 per gram.

So an estimated gold value of 138.75 grams x $57 = $7908.75.

So How Many Models To Choose From?

If we're looking for a vintage piece there are three GMT-Master references to choose from - the 6542/8, 1675/8 and 16758. We'll exclude the GMT-Master II and the modern-classic 16718, and subsequent 116718.

The gold 6542 (cal 1065) was only offered with a brown dial. The gold 1675 (cal 1565, 1576) and gold 16758 (cal 3075) were offered in black or brown. So five models, using four movements, spanning 40 years of production. This narrows things down considerably.

GMT-Master vs GMT-Master II

The main difference between the outgoing GMT-Master (16758) and incoming the GMT-Master II (16718) is the adoption of the movement cal. 3085 in the 1980's.

In addition to technical enhancements, the main marketable functional advances were the quickset date and GMT hand. The GMT-Master II is not generally considered vintage but rather neo or modern-classic. These 5-digit references are transitional in the sense they retain many vintage characteristics, and are visually distinct from the contemporary GMT-Master II like the 116718LN.

If you are not a fan of the iconic nipple dial then the more contemporary GMT-Master II is for you. These later models are generally more abundant, in better condition, and command lower prices.

It is important to understand Rolex production processes evolved rapidly from the late 1990's onwards. Process automation and quality control became more sophisticated resulting in a more uniform product. This high level of engineering is very apparent in the look and feel of modern references.

Vintage watches by comparison show far more variation in their finishing, and gold cases were meticulously hand polished. Small variations can be seen between watches of the same batch (close serial number ranges). Oyster cases were seldom perfectly symmetrical and the width of lug chamfers could vary. While this is also true of stainless steel equivalents, the effect is more pronounced with gold being softer.

reference 16718 black dial on jubilee
Vintage GMT-Master 1675/8 (1970's)

This is an attractive, typical example in average condition. It has some service replacement parts suggesting it's been cared for. The case and bezel appear polished and worn, consistent with wear and servicing. The lugs are asymmetric and less than crisp. The Jubilee bracelet is stretched. Overall, this is an honest example of a 50 year old watch in good running condition. This is a good candidate for regular wearing, or a restoration project.

reference 16718 black dial on jubilee
Vintage GMT-Master 16758 (1980's)

This case appears to be refinished (milled or recut) and a little too sharp and crisp for its age. The finish of the top surface of the case is more brushed than satin, suggestive of a retouch. Given the softness of gold, this case is too clean to be unworn or unpolished. The service parts also suggest it's been used, worn, and worked on. Skillful, sensitive restoration is not bad and can restore life to a tatty watch. This is an attractive piece.

reference 16718 black dial on jubilee
Neo-Classic GMT-Master II, 16718LN (1990)

Early versions of the 16718 can be found with tritium lume but Luminova had been adopted by the time this reference was retired. This reference offers modern conveniences like quick set date and GMT hand and is the first of the clicking bezels. It is the last of the classically-shaped Oyster cased GMTs.

reference 116718LN anniversary green dial
Modern GMT-Master II, 116718LN (2005)

The green dial anniversary edition had adopted Super Luminova as the lume material, which was replaced by Chromalight in 2008. The maxi-style case and dial appear larger and the chunkier Triplock crown is easier to use. Combined with the ceramic bezel, the appearance and wrist presence is more substantial.

The Vintage GMT-Masters In Solid 18K Gold

Reference 6542 (1954-1959) Caliber 1065

This reference was originally launched with radium lume material on the dial, hands and Bakelite bezel. This radioactive material was the subject of a service recall in the 1960s. Most surviving examples have had their dials, hands and bezels replace by Rolex with safer tritium versions. Bakelite bezels are known to be fragile and prone to cracking. Nearly all examples of this reference will have replacement bezels and any surviving original examples are generally in poor cosmetic condition. So the notion of all original is not really relevant to this reference. A buyer should focus on authenticity and aesthetic appeal.

This reference has a slightly smaller 38mm case and classic alpha hands. These characteristics are so typical of the 1950's aesthetic.

Source merchandiser (TRF)

This example was co-branded by Caracas retailer, Serpico y Laino. These are highly prized and command a price premium. This example has a replacement red GMT hand (rather than gold).

Source Phillips

This exclamation dial features a small dot of tritium lume below the six o'clock hour marker, giving its name. It is thought to be a Rolex service replacement from the 1960's during the radium recall saga.

Source David Parmegiani

This beautiful example has aged to a deep red and illustrates the open sixes so characteristic of vintage date wheels.

Reference 1675/8 (1959-1979) Caliber 1565 & 1576

During the 20 years of production the 1675/8 experienced two notable design changes to the hands and the Oyster case crown guards. The anodized aluminum bezels are more durable than Bakelite and many have survived in good cosmetic condition.

The main criticism of this reference is the slow setting date and GMT hand. Setting both involves winding the watch around 24 hours. While this may not be a major irritant on March 1st, it can be quite a chore if left unwound for several weeks.

Of the three vintage references, this is the one that most interest collectors. Within the reference there is lots of design variation, prices are reasonable, and examples are plentiful in a range of conditions. The 1675/8 embodies the charm of a truly vintage Rolex.

1960's 1675/8 matte brown with alpha hands

Source: Phillips
Earliest versions (this one from 1960) had no Oyster case crown guards. The hour and minute alpha hands are unique in the Professional tool watch collection.

1960's 1675/8 matte brown with batten hands

By the mid 1960's the hour and minute hands had been changed to the broad batten-style hands. The minute and GMT hands were left unchanged.

1960's 1675/8 matte brown with Mercedes hands

By the 1970's the now familiar Mercedes-style hands were introduced along with the more familiar lollipop seconds hand and large arrow GMT hand.

Reference 16758 (1979-1988) Caliber 3075

The 16758 was a transitional that spanned the gray zone between vintage and neo-classic. The first versions are visually quite distinct from the last. An important difference from the outgoing 1675/8 is the coronet is no longer applied gold like the hour markers, but gilt etched like the text and minute track. The main functional improvements that came with the cal 3075 was the quickset date (but not the 24 hour GMT hand).

16758 matte nipple dial

Early versions resemble the outgoing 1675/8 with matte dials. "SWISS - T<25" beneath the 6 o'clock marker replaced "SWISS" of the 1675/8. The most obvious upgrade is the sapphire crystal.

16758 glossy brown nipple dial

In the 1980's the dials assumed a glossy sunburst effect. While these are striking, they don't age well. Corrosion has given rise to the Tropical Dial. While some are beautiful, many received service replacements.

16758 glossy brown gold surrounds

Towards the end of the run dials received the familiar lume plots surround in a gold ring. This came to be referred to as the glossy dial. Tropical dials of this style are common.

Lets Talk Dials

Dials were manufactured predominately (but not exclusively) by Bayler. Dials are held in place by two prongs or dial feet on the back. These slot into holes in the movement beneath. The position of the prongs and holes is specific to the movement. So a dial with feet positioned for caliber 1575 will not fit caliber 1065 or 3075. Dials are generally not interchangeable between references. However, prongs can be removed and reattached, or dials can be held in place with sticky dial dots. So it is possible dials can end up in watches they were not designed for. However, it is easy enough to swap a black dial for a brown one within the same reference.

Generally the earlier matte-finished dials age better than the glossy sunburst variants. Both can be found in good original condition but the popular tropical dials tend to have started life as glossy sunburst versions.

mate black nipple dial

The black matte nipple dial is classic and also found in the two-tone 1675/3 and stainless steel 1675 models. They can lighten with age but generally do not become tropical. The dial feet are in the correct positions for caliber 1575 in a reference 1675/8.

Bayler dial back and feet
matte brown nipple dial SWISS markers

The matte brown dial is unique to the vintage GMT-Master. The earlier versions had the "I" of "SWISS" integrated into the 30 second marker. This is one of the indicators of an original, early tritium dial.

dial plate rear
shiny brown sunburst dial SWISS markers

The later sunburst-style glossy dials feature a different "I" in "SWISS". This is also seen on some service replacements of the matte brown dial too.

Brown glossy back

This matte brown dial for a 16758 has damage characteristic of mishandling. Perhaps carelessly stored with other sharp, loose parts.

The gilt coronet, "SWISS - T<25", and the position of the dial feet for caliber 3075 make this a dial for the 16758.

The back of these later dials are engraved with serial numbers rather than the manufacturers stamps.

dial back engravings dial feet position

This rare hyphen dial has been tampered with. The "I" in "SWISS" appears to have been painted to make it appear earlier.

This cracking can occur when a dial is cooked in an attempt to artificially age it. Cracks result from rapid heat expansion of the dial plate before the paint can soften. Cracked dials may be described as spider dials and should be avoided in GMTs.

With these two red flags, authenticity of the hyphen and provenance of the dial in general is highly questionable.

Service dial 1675 Service dial SWISS text

This is a service dial for a 1675/8. The "I" of "SWISS" is offset or misaligned with the 30 second marker, which is typical of service dials. Position of the dial feet is correct for caliber 1575 and it has an applied coronet.

Later service dials are engraved on their backs, like the later 16758's which will replace them.

Service dial back engravings Service dial back

The Truth About Tropical Patina

Tropical

Source: Hodinkee
"There's something that just can't be beat about a product built to last showing its age, and watches bearing tropical dials are a perfect and particularly desirable example of this."

It is true that some signs of age add character to a gold watch but be wary of descriptions used by sellers. What is considered desirable, attractive patina in a steel GMT-Master, does not translate well to a high-end sold gold GMT-Master. A heavily distressed gold watch looks tatty, where equivalent patina on a stainless steel GMT-Master can look cool.

While unpolished gold GMTs are desirable, it is not so egregious to polish one provided the work is of a high standard. The line between good and bad can be thin, but the goal is to maintain as much presence and charm as it originally had.

Use of the term tropical is especially common with sunburst dials. Use of the word patina is more commonly used to describe the condition of tritium lume and therefore associated with later dials featuring more tritium lume. Both terms are euphemisms for corrosion, which we should remember is a constant ongoing process. And like rust, will continue unless treated. Corrosion that may be minor (or attractive) today, could be catastrophically ugly in a few years.

Corrosion is a natural phenomena and should not be confused with damage. Unscrupulous sellers may try to conflate the two. Attractive corrosion like the Tropical Dials above can command a price premium based on their aesthetic. Damage never does anything good for long term value.

If you are considering a Tropical dial, aim for overall evenness, uniformity and consistency. Never pay a premium for a damaged dial caused by mishandling. Unless the rest of the watch is compelling (very attractively priced) move on.

Tigers Eye

There is some debate over the two-tone bezel and if it was officially sold on the gold GMT-Master. Some argue it was reserved for the two-tone models (the Rootbeer). Others claim to have original examples similar to this.

Bezels

While bezel inserts may seem a small thing, they are an integral part of the overall design and strongly influence valuation. Loose bezels in good condition sell for several thousand dollars. Replacing an incorrect, damaged, or fake bezel can be a time consuming and expensive project. Particularly on early references.

Bezels were designed to be consumable and were often replace by Rolex during servicing. They are easily changed and owners do this out of personal preference. Original bezels are highly prized but rare. Service bezels are acceptable and common. Fake, after-market (non-Rolex) bezels are to be avoided. Distinguishing between them can take a trained eye and buyers should seek input from Rolex forums if in doubt. A full discussion of bezel variants, eras, and fakes is worthy of its own book and beyond the scope of this discussion. At the time of writing, this post by Xeramic on VRF is one of the most comprehensive analysis on the internet .

All versions of the GMT-Master feature a bi-directional bezel. These were friction fit (non-clicking) until the arrival of the modern classic reference 16718, with the 120 click bezel. It is correct for transitional models like the 16758 to have the older-style friction fit, non-clicking bezels.

Bezel Dimensions (1675/8, 16758)

  • Outer diameter ~37.75 mm
  • Inner diameter ~30.2 mm

What we know for sure is the Black-Gold and Brown-Gold bezels are correct for the gold GMT-Master. While the Black-Silver is not incorrect for very early serial numbers of 1675/8, it is most likely from a stainless steel model. Brown-Silver is also seen on early 1675/8 references and while no catalog evidence has yet surfaced, the collector community consider's it legitimate. Some examples are gold faded to silver, but a few are clearly silver. In some circles Brown-Silver is considered rare and commands a price premium.

Black & Gold
Black & Silver
Brown & Gold
Brown & Silver
Two-Tone

Crowns

Despite the Oyster case crown guards, the gold winding crown is prone to dents and wear. They're often polished (sometimes badly) during a service. Crowns and crown tubes are considered consumable components and were designed to be replaced. Authentic service replacements can be found but you're advised to search Ebay to get a sense for what they're going for, before asking your watchmaker to source one. Having said that, don't be put off an otherwise nice watch for a dented or polished crown.

Twinlock symbol

Symbol for the Twinlock crown

Twinlock Crown

Don't expect crowns to line up once screwed down.

Twinlock Packaging

Typical blister packaging for Twinlock Part Number 24-603-8.

new Twinlock

An unused new Twinlock ready to be installed (P/N 24-603-8).

Twinlock Stem

A genuine Twinlock, stem and tube from Ebay.

new style packaging

Modern packaging is more utilitarian and sophisticated.

Twinlock RFID tag

The newer packaging includes an RFID tag for supply chain tracking.

polished Triplock

A heavily polished Twinlock ready for replacement.

Casebacks

Casebacks are interchangeable between the 1675/8 and 16758 models. Later models have the same dimensions but different threads. They have a stepped appearance featuring a mirror polish and a satin finish. Casebacks will always be 18K gold and engraved with Rolex marks and the Geneva Assay Office hallmarks.

Caseback 1955-1982
1955-1982
Caseback 1982-2005
1982-2005
Caseback 2005-Present
2005-Present
6452 caseback

6542/8

1675 caseback

1675/8

16758 caseback

16758

16718

16718

The GMT-Master caseback has a stepped profile with a combination mirror polish and satin finish

Don't be distracted by convincing-looking caseback stickers. Focus on the Hallmarks

Genuine and counterfeit stickers are available on Ebay

16718 sticker

Stickers vary by era and model, making authenticity difficult to establish

Embelishment

Movements

The inner workings of the watch are seldom of interest to collectors. However, visually recognizing the right movement for a watch can be very helpful.

Caliber 1065
Cal 1065

Caliber 1065 was the first of the GMT movements introducing the fourth 24 hour hand reference 6542. It was derived from the 1000 series base movement, and the 1065GMT was one of the last iterations. The most obvious distinguishing characteristic is the butterfly rotor.

caliber 1576
Cal 1576

Derived from the base caliber 1500, the 1570 introduced hacking and the 1576 the fourth GMT hand.The 1576 was also used in the Explorer II. The bridge of the movement is stamped "1570".

caliber 3075
Cal 3075

Used 1981 through 1988 and then replaced by the 3175. This caliber introduced quick setting date but not the 24 hour hand. The hand stack changed with the GMT hand now above the hour hand.

Oyster Case Hallmarks

Hallmarks should be present on all Rolex made of precious metals. They appear on mid-cases (underside of lugs), casebacks, bracelets, and clasp blades. The absence of hallmarks indicates gold cap, gold fill or gold plate. Mismatched hallmarks suggest a Frankenwatch assembled from various parts.

Hallmarks are defined by an official Swiss government assay office and applied under license by the manufacturer (Rolex or Genex). There are seven assay offices in Switzerland and Rolex uses the Geneva office exclusively. The symbol for the Geneva assay office is a capital G, which will form part of a larger hallmark.

Helvetia Assay Mark

Barry

Barry Assay Mark

A Swiss assay hallmark is exceptionally detailed, which makes it very difficult to copy. It must be consistent and flawless with each stamping. The assay office controls the quality and if not perfect, the item will be scrapped and cannot be sold. The crispness and detail of a hallmark are essential in establishing authenticity.

Solid 18K (750) gold GMT-Masters will have the Helvetia Bust (lady’s head) with a capital “G” below her neck

Current Swiss law (post-1995) has reduced the number of hallmarks to a single mark, the head of a St. Bernard dog. The Office of Precious Metal Control refers to this St. Bernard dog as “Barry”. It appears near the Maker’s Responsibility Mark and their indication of purity. Barry can be found on the underside of lugs and on the caseback.

Rolex watches imported into other countries are subject to local assay or customs office inspection and may carry hallmarks in addition to the Swiss ones. For example, watches imported for sale into France and England would have additional, but different hallmarks.

Manufacturers 18K gold purity mark

Manufacturers 18K gold purity mark.

Helvetia mark from Swiss Assay Office, Geneva

Helvetia mark from Swiss Assay Office, Geneva.

Assay gold purity. The number '750' between a set of scales

Assay gold purity. The number "750" between a set of scales.

Importing country assay mark. 'C' indicating South America.

Optional importing country customs assay mark. "C" indicating South America.