as a counterpoint to Bill and Nico's pictures, here's my 6536/1 with tropical gilt dial. It makes me think I should pick the watch from the bank vault and give it some wrist time in 2015....
the case is unpolished, with very wide bevels the dial has a spiderweb effect the Watch has a strange history. I got it some 10 years ago from a watchmaker that used to work for the French Navy. The case does not have any engraving between the lugs, neith...
...and you sometimes see quite unusual mixtures or repairs on these pieces. Another lead is the fact that the 7922 Big Crowns had typical 6538 serial numbers, which is another mystery concerning the Rolex / Tudor non crown guards Subs.