Dating Hamiltons can be very difficult, I have found you have to ask them out at least three times and promise them a good dinner and at least a movie before they will even consider going out with you. Seriously, I am not sure if there are any publications that can put a date on the Hamilton military products. I have found a website that does date the 4992B here: http://www.oldwatch.com/Hamiltongrd.html
I have matched up some of my 4992b watches and found them to be pretty close. I also heard that with some of the 4992B watches that the case dates do not always match the movement.Apparently it was not really important to match up each movement with the original case when a few 4992b watches were being worked on at the same time. There might be some book out there I don't have that may help, perhaps one of our Military colectors can help.
Pocket Watches Moderator
According to Whitney's "Military watches"
The Model 23 was started in 1943 and by Dec 31,1956 the number had reached 23,146 Watches.
As for the Ships Chronometer that was made for commercial sales after WWII was over.
I have seen the numbers,but where I cann remember now.A senior moment, no doubt.
The military models you have listed (Model 22:2F12604; Model 238334; Model 4992B:4C88345) were all serial numbered separately from the commercial watches. All of the common published lists are for commercial watches.
I don't know of a published list for these, although you can get an idea about the Model 22 from Whitney - about 23,000 Model 22's were scheduled to be delivered in 1941 and 1942 - but actual delivery dates are not given. From this, one might infer that yours was made during WWII. Whitney adds that 28,773 had been delivered by 1956.
Most of all three of the models you mention were made during WWII, although some production continued in the 1950's and possibly later. Many of the cases have a date which is the date that the contract for manufacture was awarded. If the case and movement are original to each other, the contract date is the oldest possible date for the timepiece
The late Bob Ravel had detailed information on the Model 21 chronometers, but I don't know where the information is now. Most M-21's were made for the Navy during WWII, but some were made for other purposes after the war. As Julian has indicated, the serial number you list is post-WWII.
[This message has been edited by Larry Jones 98326 (edited 10-02-2001).]