Has anyone ever heard of or seen a World War I Hamilton GMT pocket watch? Was there such a thing before WWII?
This one as described to me is "suspended by 3 springs in a steel case; has a US military brass plate on side, dial has 3 letters..."

Make any sense?

kh

sounds like it's a WW2 Hamilton navigation watch - the case as described sounds like a WW2 Aircraft Navigational Watch Carrying Case made by Adamson as the one below posted on IHC by Mike Rouse in 2012 in which you can see the brass plate on the side and the shock protecting springs.

That must be it, Tom, as described. And I did think the seller meant WW2. Thanks!

KH

Yes, as Tom has said it is definitely WWII. I have noticed that there can be a fair amount of confusion among sellers who are not collectors of military timepieces and also buyers where they can get a bit excited and either believe old vet stories, family tales, or imaginative sellers trying to get the best price. WW II things get advertised as WW I, 1960s to 1990s timepieces get advertised as WW II, or timepieces get advertised as having come from famous aircraft such as Spitfires, Mustangs, B-17s, etc. when most timepieces are generic and could have been used on anything from a famous fighter or bomber, or just as easily from a transport, a trainer, a reconnaissance, a liaison, or one of the great many more non-combat aircraft that were around.

In the title of this thread - WW 1 Hamilton Pilot - there is another error beyond it not being from WW I, and that is the word Pilot. Again as Tom has advised this would have been used by a navigator. It would not have been used by a pilot. Pilots had clocks in their instrument panels which is what they used for timing. Their clocks, like all of the clocks on board an aircraft would have been set according to one of these so that they all provided the same time.

Thank you for that info, Jim (and thanks to Tom earlier). Although I did not believe what the seller said for a minute, I did not know the truth or the background either.
kh