From the serial number, K401XXX, it would appear to be a K-22 mfg'd in 1960. The odd color on the hammer and trigger is what is referred to as "case color hardening." A picture would enable some to make a rough guestimate as to its value. It should be a Model 17-1. You can locate the model number when you open the cylinder. It's on the frame opposite the crane. A very desirable gun to hang on to.