amanico[JLC Moderator]
402079
Welcome here, TH. Richard gave you a good answer. Auction houses, and the different collectors markets, plus Ebay, Chrono 24 and the watch shops, on line or not. It is a huge challenge...
And not sure, in case you find it, you will have some rights on it; if the buyer is in bona fide ( good faith )....
Best,
Nicolas