Thanks everyone for a of your input. I had no resources to use. Although I did mean to clarify that it does for sure say Secret Service Special. and according to my dad there's a date of May 1940 or 1970 I can't remember the exact. It for sure doesn't say for S&W cartridges though. If it also helps, I may have a serial # but it is illegible now. The barrel looks blued but worn. There is a pretty large safety. Again, thanks for the input.