Help with a 1978 GMT Master 1675

[NickTruswell]

Hi Everyone,

I'm looking for a bit of help on a 1675 from 1978 that I'm interested in. I've posted some pictures below. Could you let me have your comments on the watch's originality, particularly the dial, hands and insert. Watch is with box & papers.

I am a bit of a novice on vintage so I'd like to ask the experts for their input.

Here's what I've managed to figure out for myself;

Insert looks correct with the painted line running through the number 8 rather than between the 1 and 8.

Correct silver date wheel

Not sure on the dial, I thought a 1978 would be in radial dial territory but as I say I'm no expert.

The hands look like a few shades darker than the dial, could this mean on or the other has been changed?

The box and paper's look about right for that time period.

Thanks for your help
cheers
Nick

[NickTruswell]

Bump, hoping Springer will take a look
Cheers
Nick

[lee fowler]

I think it is to late for a Radial Dial, what are the first three from the serial number?

[NickTruswell]

Originally Posted by lee fowler

I think it is to late for a Radial Dial, what are the first three from the serial number?

Not sure Lee, its not mentioned in the description on the web site. I've just looked at ochi's sticky on 1675 dials and I think you are right, too late for a radial dial if its a 1978. Radial's should have finished in the 4m serial range.

I think it looks like a mark 4 dial based on ochi's post which would be correct for 5 - 6m serials.

Do you think it's had a polish? the crown guards look fairly strong but the bevels on the case look like they've almost been smoothed over now.
cheers for the help
Nick

[77T]

Yes the hands have the patina one might expect with 30+ years age. Often they get replaced sometime during a watch's overhaul - but then they'd be lighter than the dial. It makes you wonder on that point - at least regarding complete originality.

The dial may have been refurb'd once - perhaps lume touched up?

But to your main issue of radial dial being correct for this one - you'll need seller to open up those papers and send a scan to you. How did you come to dating it from 1978? Was that the seller saying so? Or do you know this one's SN?

Yes it has been polished during an overhaul at least once.

And unless you get a look at the clasp code you could have a replacement bracelet - not a biggie to me personally but maybe more to your originality question.


Sent from my iPhone using Tapatalk

[springer]

The dial is a Mark IV which could very well be correct for the watch. The red hang tag is incorrect and is a much later production tag. The box set, which is a USA Bufkor box with the large leather-grain pattern, is from the early 1980s.

The watch has been polished in the past and is not unpolished.

[Swearengen]

Originally Posted by springer

The dial is a Mark IV which could very well be correct for the watch. The red hang tag is incorrect and is a much later production tag. The box set, which is a USA Bufkor box with the large leather-grain pattern, is from the early 1980s.

The watch has been polished in the past and is not unpolished.

Note careful wording from the seller "both original swing tags still attached, comes complete with an original Rolex box, instruction manual and undated Punched Papers." (my underlining)

Should we be worried about the undated punched papers too?

[NickTruswell]

Originally Posted by Swearengen

Note careful wording from the seller "both original swing tags still attached, comes complete with an original Rolex box, instruction manual and undated Punched Papers." (my underlining)

Should we be worried about the undated punched papers too?

I wondered this myself. Thanks for the input everyone, definitely passing on this one
Cheers
Nick

[phillip ridley]

Here is a cool article going over the various Luminous Materials.

Radium:

Up until about 1960, Rolex used the radio-active material Radium to coat hands and indices of their dials. The Radium markers were extremely efficient where bright luminosity is concerned, but also much more radio-active than the successor, Tritium.
Workers at the Rolex manufactory and other watch and clock shops, applied the Radium by hand; or rather by using a fine painting brush. To apply the Radium exactly to the places where it was supposed to be, workers would tend to lick the tip of the painting brush to get a sharper point, thus being better able to apply more accurately the Radium. This habit of licking the painting brush resulted in numerous cases of workers getting cancer, especially mouth cancer. But as stated, Radium was used up until 1960, where popular use finally ceased due to serious health risks.

The dials having Radium as luminous markers would read "SWISS" at six o' clock.

Tritium:

Tritium was used from 1960 to 1998. Also being radio-active, but more mildly so (beta waves). The half-life is approx. 12.3 years. After that, Tritium (in most cases) will not glow anymore.
There were two degrees of Tritium dials:

a) the dials emitting radio-activity of less than 25 mC. Dials are marked "SWISS T < 25"

b) the dial emitting radio-activity of less than 7,5 mC. Dials are marked "T SWISS T".

To describe the intensity of the radio-activity of the Tritium markers, a thin sheet of Aluminium is able to block Tritium beta waves. Thus, the Oyster case and crystal were said to be sufficient guard to prevent any harmful radiation to the wearer of the watch. The radiation a person gets from the normal background radiation found in nature exceeds the radiation emitted from a "T < 25" dial.

As a side note: Besides the "half-life degression" of the Tritium, hands and indices applied with Tritium have often been known to discolour to a more brownish tone by age. Some say that factors like UV rays and humidity play a role. Therefore, not ALL Tritium dials discolour. It depends on what environment the dial / watch was kept in.

(Super)Luminova:

A Japanese invention from the company Nemoto, the non radio-active substance, Luminova, was introduced in 1998 when Tritium was (at least widely) banned. Time spans for the use of Luminoa is:

a) 1998 - 2000: Dials (again) marked "SWISS" at 6 o' clock

b) 2000 - : Dials marked "SWISS MADE" at 6 o' clock.

The terms "SuperLuminova" and "Luminova" describe the same paint compound. Technically, there is no difference between the two, but "SuperLuminova" is a term reserved by Nemoto's European partner, Tritec.

SuperLuminova is not (yet!) known to discolour by age. But SuperLuminova is quite fragile and does not like humidity which can make it crumble. Some companies solve this issue by applying a thin coat of clear lacquer to the markers of the dial.

Phillip Ridley,CW21
Watchmakers International