I just purchased a 12-2 two inch dated to 1972. It has the correct non-diamond grips numbered to the revolver. The question is, on both halves the letters "KAS" are stamped. Just wondering if this is an inspectors stamp or something else.
The Model 12 was an aluminum alloy K size frame. But the dimensions of the grip frame were slightly different than the steel K frame, so this frame was called by S&W the KA Frame. The stamp you asked about is KA Frame, Square Butt (hence, KAS).