As vintage Rolex collectors, we have a keen interest in Rolex production variants. There is one very rare modern GMT that I find particularly interesting---the classic 16710 with new 3186 Blu Parachrom movement. The existence of these watches has recently been speculated, but until now not confirmed.
It was thought that one reason Rolex increased the case thickness for the new 116710 was to accommodate an increased height of the 3186 calibre. But as you can see from the included photos, the 3186 fits nicely in the older case.
I believe these watches are a rare anomaly of Rolex production. I know of 4 examples. All 4 are M serials. 2 came with black bezel and 2 with Pepsi bezel. There is no notation on the paperwork or otherwise to indicate they have the 3186—-you have to open the watches to confirm. Another possible example in Finland (with Z serial) has been mentioned.
Some have noted there may be a difference in feel of the crown between the 3186 and older 3185 movements when setting the hour hand, but I would say that confirmation requires opening the watch.
You will also notice that the pictured watch has an unusual dial—-the "II" of "GMT-Master II" is in "non-roman," or "stick" font. I have seen a few other watches with the same dial, presumably without the 3186. Interestingly all 4 of the noted 3186 GMT II’s have this dial variant.
So common external factors thus far of the 3186 GMT II’s I have seen are M serial and "stick II" font dial, though this is not to say that all watches with these traits have the 3186 movement. It is not clear to me whether the potential Z serial example mentioned above has been documented (and dial unknown at the moment). It would be interesting to see pictures of that watch.
I have no information why Rolex may have produced these watches. Some have speculated that they were a test prior to the new 116710 GMT IIC, but this would certainly not seem correct given the late production. Some have also speculated that Rolex had more 16710 cases than older 3185 movements to match, but I also doubt Rolex has run short on the 3185.
As some reassurance to those who may remain skeptical about the authenticity of these watches, the pictured example has been examined and confirmed by a Rolex AD, Fourtane Jewelers in Carmel, California.
Time to open some case backs...... Please post pics if other examples are found.
