I have just acquired a Hamilton Model 22 gimballed type (but not with gimbal or case unfortunately). I am fascinated by the watch coming from a nautical background. The movement serial number is 2F1491 which I believe dates it at 1941? I am puzzled though that the engraving on the movement does not include 'US Navy Bureau of Ships" which seems to be on every example that I have seen pictures of so far. Also the case back is unmarked. My example has been sitting in a drawer for at least 35 years.

Hamilton made both gimbaled and ungimbaled varieties of the Model 22 with the gimbaled being the more common of the two. They also made them not only for the US Navy, but also the US Army, the Canadian Navy and the Russians as well. And they made a great many for civilian use.

I do not know enough about dating the movements of these but if yours dates to 1941 and has no military markings then I would think that there is a good possibility that it was made and sold for civilian use. Remember that the US did not enter the war until December of 1941 and while there was some military production as well as civilian production going on in 1941 the US did not ramp up for war production until early 1942. Perhaps there is a record someplace I do not yet know about that lists serial numbers for Model 22s that were manufactured to fill specific military contracts that might help, but without such my first thought would be your movement was sold to a civilian buyer. The military was pretty strict on ensuring all of their valuable timepieces were full marked with military markings to deter theft.

Thanks Jim, that would make sense. Within the space of a few days I have gone from never having heard of the Hamilton 22 to reading a whole lot of info! I believe there are detailed ledgers of serial numbers available.