Father In Law has a 1940/42 Luger

[georgespelvin]

I am trying to help my Father-In-Law figure out the origin and value of a Luger his uncle (a Merchant Marine Sailor) gave him in 1942. From the markings on it, it appears to be a 1940/42 model, with a serial number of 979. The Proof markings seem to match the #46 or #47 examples shown on this site, which would make it a Military Proof. Under those markings are the numbers 655 and either i55 or 155.

I'm not a gun collector, but there would appear to be some wear on the handle, which is the brown walnut color. The clip is missing a couple of rounds, so I am assuming it was used at some point, although my Father-In-Law has not fired it once since it was given to him in 1942.

Any help would be appreciated.