I found a 5" barrel K frame, serial # C104xxx, wearing diamond magna stocks, blue steel. Several small spots of surface rust along the RH side of the barrel and frame where the barrel screws into the frame. LH side is clean as a whistle. Faint cylinder line, locks up tight, possibly tighter than any S&W I have ever owned or handled. Is this a pre #10? DOB from around 1949-1950? Is it worth $300.00 + tax? Thanks.