Welcome to the Forum! The K38 Combat Masterpiece was manufactured between 1949-1957, and then became the Model 15 Combat Masterpiece from 1957-1999. The only barrel length was 4" until 1964 when the 2" was added. The 15-2 was introduced in 1961, and yours (s/n K4951xx) is from 1962. This is an interesting time for the Model 15s, as many were purchased by the USAF and other gov't and law enforcement agencies. Have you checked that revolver closely for any agency stamps (U.S.A.F., DPS, CID, etc.)? The USAF in particular purchased large numbers of 4" bbl. 15-1, 15-2, and 15-3 revolvers from 1960-1969. Any military provenance would greatly increase its value. We have a 2" Model 15-2 that was the EDC for my wife's grandfather...a Calif. LEO and Chief of Detectives. The frame (s/n 509199) was manufactured in the middle of the production range of the rare U.S.A.F. 2" Model 56 (500001-515205), but the 2" barrel wasn't commercially available until 1964...when this particular revolver was shipped. Chances are that our revolver was supposed to be part of the U.S.A.F. Model 56 production (15,205 revolvers) but ended up going to the police instead, and it does not have the "U.S." stamp. Apparently most Model 56s were destroyed by the gov't. and only a few survive. In it's described condition, and if the price is right ($450-$500), I wouldn't be afraid to take a chance on that Model 15-2. Good luck with your decision.