My grandpa just gave this to me to keep. It is a Ruger Mark I .22 Target. Serial # puts it in 1954. I think he's owned it since then. I never knew he even had this. I have no idea where the holster he used, came from. It looks altered and VERY old. Any ideas on the holster? Not a particularly valuable pistol $350 or so) but a nice one never-the-less and worth holding onto. It feels very solid in my hand. Certainly a nice addition.