On page 230 of the 2012 Price Guide:

960, 21J, LS, BRG, GJS, OT, DR, Adj.5P, OF

Can someone tell me what "OT" stands for? The only other Hamilton showing this notation is the 990.

I think it's a typographical error in the book, it should be "GT" . . . compare to the listing for the hunter version of the same watch, the 961.

If you check the list of abbreviations on page 101, "OT" is nowhere to be found.

GT = gold train

Thanks Ed.