Bought a 639 back in 1986 while stationed in Germany. Took it to the range recently but noticed that the RH safety lever was missing. Went back to the range but couldn't even find the screw. My efforts to find replacement parts has gone negative as S&W and two other vendors have been out of stock. One of the vendors couldn't even tell me about substitute, interchangeable parts from other models. I would appreciate if a 639 owner here points me in the right direction. Thanks