I'm new to this so please be patient with me. I'm trying to find out more about a 1915 Hamilton 21 deck watch /chronometer but am having great difficulty. I can't find any historical documented information (i.e. how many were made, why, and their rarity etc). From what I've gathered - depending on its casing construct, it served both as a pocket watch as well as chronometer. Was this their 1st version of a chronometer? Everything I learned has been verbal as I can't seem to find any valid documentation - it's as if this piece doesn't exist. The serial # is 1260835 and the piece is in excellent working condition. Any assistance and/or pointing in the right direction would be greatly appreciated. I can post/send pics if you like - I just don't know how to yet.