Have RR. 1943. Sn.946XXX. Sn. Large S & N is about half size of S it is underline like the earlier before factory shut down. Slide is the Type II. My question is it has a type 6 colt barrel ( left side Colt 45 Auto also P, bottom of barrel marked S which I think is a commercial barrel transferred to the military. Any input on the barrel would be appreciated. The grips or of later Keyes Fiber with reinforcement rings.