I have a pre-war Smith that needs a launch date. So far I have determined that it is a .38 M & P Model of1905 - 4th change. It has 5 screws and a 4 inch barrel with fixed sights. It is chambered for the "38 S & W SPECIAL CTG" and the S/N is 395147. Standard Catalog places it 1915 - 1942. Can anyone narrow the time down to a couple of years rather than decades? Thanks, Jim