I have recently taken on a Rolex GMT as a project, and have found out so far that it is a e 1952 example I believe this is called a Y series drilled lugs. The 4th hand to indicate the 24hr dial. Is this the standard type GMT?,
a particularly early example?
What was the first year of production for a GMT?
(Sorry no pictures at present)

Chris, you might want also to post your question to TimeZone's Vintage Rolex message board. There are a lot of specialists who contribute there. According to the Dowling and Hess book, "The Best of Time", the first GMT-Master (Model 6542) was produced from 1956-59, and was based on the slightly earlier Turn-O-Graph.

Adam

Thanks Adam,

Will try there and see how far I get.
will post if I find out anything intresting.