I applaud your efforts.
The three production 1680 white dials are fairly well documented, Mk1, Mk2, and Mk3.
When identifying these dials I try to focus on a few characteristics: the shape of the coronet, the position of the L in Rolex under the coronet, position of the = sign underneath the A in the depth rating, and how the CERTIFIED text lines up under the CHRONOMETER text.
For the Mk1: the L is directly under the coronet, the = sign is directly under the A, and the CE in CERTIFIED line up directly under the CH in CHRONOMETER. Of note the 6's are closed.
For the Mk2: the coronet is a totally different shape than the mk1, the L is shifted to the left under the coronet, the = sign is slightly to the right of center under the A, and the CERTIFIED text is slightly shifted to the left under the CHRONOMETER text. Please note that the 6's appear closed but upon magnification they may be semi closed much like the mk5 red sub. Also note there have been some dials called mk2 dials with a slightly different coronet.
For the Mk3: the coronet has a distinctive shape and the L under has a bunch of serif on the top. To my eyes the L lies just to the left of center, the = sign is slightly to the left under the A, and the CERTIFIED text is shifted to the right under CHRONOMETER. Please note the sixes are closed.
The reason I look at all these characteristics of a given dial is because when people fake a dial for the most part they will combine different characteristics of a couple dials into a fake dial. For instance if you saw what appeared to be a Mk1 white dial with all the correct characteristics but upon closer examination you realized that the CERTIFIED text was shifted to the right under CHRONOMETER you would be correct in calling it an incorrect dial.
The service dials remain a bit of an enigma because for some of the examples there weren't just that many of them made and not many owners who have them have openly inquired about their authenticity. A few years ago I received an email from a guy asking about his 1680 white dial. It did not fit any of the characteristics of the dials I had seen before, but it looked too good to be a fake. I shot a pic to Marcello, and he confirmed for me that the dial was in fact a seldom seen service dial.
The characteristics I have found in the commonly seen service dials are the following: typically the L is shifted to the left under the coronet, in some cases way to the left, the 6's are many times open or semi closed, and the F extends over the t in feet in the depth rating. This is a readily seen characteristic in many service dials that is also seen in Sea Dweller service dials as well. However, please don't confuse this with the F over the T in the 1665 Rail Dial.
The "tooth paste" or "caulk" looking tritium substitute is also a sure sign of a service dial. I have some dials with the normal appearing tritium and the same dial font with the "toothpaste" appearing substitute, leading me to wonder whether both are service dials just from different time periods.
In closing here is a great thread that tackles much of the issue
http://www.rolexforums.com/showthrea...arcello&page=2
Wishing everyone on TRF a great 2017
