The SN suggests an early Outdoorsman, but it also appears to have a notched hammer like on the K22/40 Masterpiece, which would be considerably more scarce. Are you sure of the SN? I suggest that you confirm the SN from its grip frame area; it's possible that its cylinder has been replaced. Some additional photos of the frame base SN (under the grips), its hammer and rear sight would clarify this. -S2