Late 60's inner case marking IV.68

[Dadnatron]

What does the GMT inner case marking IV.68 reference?

I've heard it is date of manufacture, however, I've seen it on 1,7x and 1,9x serial #s.

Thanks,
Shane

Rolex GMT inner case stamped IV.68 resized.jpg

[Haywood_Milton]

It means that the case-back was made in the last quarter of 1968, but it could indeed be found on watches finally assembled / supplied at any time over the following year or two.

It is also possible to deduce that this watch was serviced by Rolex UK in Summer 1992 with job number 611814, which is consistent with other job numbers of that time.

Insta : haywood_milton_rolex

[Dadnatron]

Given Rolex often uses parts from previous renditions/years in later years, how is the best way to determine Year of Manufacture?

It is my understanding that there is no 'Rolex verified' reference for serial #s correlated to DOM. So how do collectors best determine date of manufacture if a case was made in 1968 and serial # is a 1,92x?

I've been using the Bob's Watches Rolex Serial number webpage as my reference.

[Kingface66]

Originally Posted by Dadnatron

Given Rolex often uses parts from previous renditions/years in later years, how is the best way to determine Year of Manufacture?

It is my understanding that there is no 'Rolex verified' reference for serial #s correlated to DOM. So how do collectors best determine date of manufacture if a case was made in 1968 and serial # is a 1,92x?

I've been using the Bob's Watches Rolex Serial number webpage as my reference.

I think most would use a combination of all you mentioned and then settle for closest approximation:
Serial Number
Case back stamp (if there’s one)
Dial design
Bracelet stamp (if original to bracelet)
Sales documentation
Etc.

End of the day, it’s always gonna be a guess.

[Tom1675]

This is a great resource
https://www.rolexforums.com/showthread.php?t=350245

[Dadnatron]

Thanks I appreciate this information.

On GMT Masters... were there MATTE service dials? And if so, wouldn't they have been 'time specific' pre gilt?

Sometimes I see Matte dials with lume much brighter and whiter, than the hands on the watch. Mark 1 dials... but almost with the appearance of a 'new' dial. Gold patina hands.

[springer]

Originally Posted by Dadnatron

Thanks I appreciate this information.

On GMT Masters... were there MATTE service dials? And if so, wouldn't they have been 'time specific' pre gilt?

Sometimes I see Matte dials with lume much brighter and whiter, than the hands on the watch. Mark 1 dials... but almost with the appearance of a 'new' dial. Gold patina hands.

Yes there were GMT matte service dials - three different dial markings:
tritium (Swiss T<25), luminova (Swiss), and luminova dials marked as tritium Swiss T<25.

There were service dials for the gilt era and the post gilt era.

Check out the Reference Library here on TRF. There is much information there to address your concerns.

Here is a thread I put together on service dials. https://gmtforum.com/viewtopic.php?f...a4be660e2d62d7

[TuRo]

Last quarter is often misprint VI as well as IV btw....

[Haywood_Milton]

Originally Posted by TuRo

Last quarter is often misprint VI as well as IV btw....

Have you seen that on anything other than a 1966 stamp ?

"VI.66" is the norm, devilish as that may be !

[TuRo]

Indeed no '66 only. 2/3 Diablo :-) as you say....

[Dadnatron]

John,

Thanks for the link. That helps me very much.

So, is it safe to say that if I see a Long E dial, it is original? Regardless of whether it appears a little 'whiter' than the hands?

Non uniform patina dial white.jpg

[lupus66]

hands and dials are usually a bit different tritium.

[Dan S]

Some dials and hands have also been relumed. There are many threads discussing the expected UV response of lume from various eras.

[Dadnatron]

I knew you could relume hands. I didn't recognize it could be done to dials. Is this common?

In the example above, the hands clearly demonstrate a gold patina. The dial, to my eye, does not.

Without actually having the ability to check under UV light, is there a reliable way to determine whether something has been relumed via photos?

[Dan S]

You can buy a small UV LED flashlight-style lamp on Amazon for less than $10.

[Dadnatron]

Heh… I meant online. I have a UV flashlight.

I don’t have the opportunity to see many vintage Rolex in person in Indiana, as far as I’ve found thus far.