I have two O.P.; one from 1944, and the other from 1967. I have some questions about the older one. It is stamped M.S.P. No. 562 on the butt. My understanding is that this was a Michigan State Police revolver. It has a 5" barrel. The front sight is a post, or patridge type. I have not seen any others with this sight. Was this standard, or a post manufacture alteration?