Hi snafu........welcome to TFF.
I'd suggest you get as much info on this firearm as possible.
The letter from his widow is a fine addition to establishing the provenance of this firearm.
You want to establish:
Did he carry this pistol in combat in WWI and/or WWII?
What were his duty postings during both wars?
Try looking up his name & rank in Google.....you may come up with something interesting that his widow forgot.
Document everying about the General and this gun that you can find out, write it down, and have his widow sign it. Provenance (everything you can learn and document about the gun and the person who owned it) may add greatly to the $$$$$$ value of the firearm.
If the General was well known, or took part in any famous operations, it could be far more valuable than you think.
BTW, a rather beat-up M1911 that was carried by the navigator of the B-29"Enola Gay" (that dropped the first Atomic Bomb on Hiroshima) recently sold for $23,000.....
......now I'm not saying your gun is worth that, or even close to that, but the provenance of a firearm can add greatly to the value, so, if I were you, I sure wouldn't sell it until you learn all that you can.