I spent a lot of time with my copy of Charles W. Clawson's book, Colt .45 Service Pistols (3rd ed.) to verify this gun. I was mainly concerned with the post parkerization marks, FJA, P and ordnance, etc., plus correct/original parts. This one passes all the tests. HS barrel, and even the General Shaver magazine, which is probably the hardest thing to find with a RR. For those who don't know General Shaver was a subsidiary of Remington Rand. RR's last pistol manufactured was NO 2465139 in 1945 and this one was part of that last contract. This makes a great companion to NO 1600035, from 1944, which my former boss gave me 20 years ago.