Looks to be early 1952 manufacture, would be considered a pre model 15. They hadn’t started giving them model numbers until around 1957. They called that model a Combat Masterpiece K38. Those do not appear to be the original grips, which diminishes the value some. It looks to be in pretty good shape for a 64 year old gun. I had one a little newer that I sold for $400 about a year ago. They have continued to rise in price so I would say still $475 to $550 without original grips. It is a very popular and sought after model.