I can't figure out what year this Tiffanys Hallmark is: http://i22.ebayimg.com/01/i/05/7a/99/d5_12.JPG On the bottom is has: Tiffany & Co. 6429 G&W ENG STERLING 925-1000 26 550 Broadway. N-Y It is not in the examples shown in the encyclopedia. It also has a different address, 550 Broadway???...