I have identified 16 of them (2" round butt) in the 625000 and 694000 range that shipped in 1946 and 1947. I have also found a few that have the prewar frames but are numbered in the S833000 range and also shipped in the mid-1940s. Then there are some in the 625000, 68100 and 694000 ranges that shipped anywhere from the 1930s to 1940 (specifically 1936, 1937 and 1940 among those I've identified). Roy says there were 100 such units that had the prewar round butt frames and shipped in the immediate postwar period. Some of them got postwar serial numbers. Many were marked with the S on places other than the butt, but none of them got the sliding hammer block safety (at least none of those that I have seen did).GB find. Wearing the wrong grips of course. Happy to have it anyway, 625000 puts it prewar if I am reading the Std Cat correct. But shipped in 47.