Lee,
You have stated above that your Transitional .357 was shipped Dec. 1948, as part of an order of 50 for the State of Kansas. Do you have a list of the serial no's in this shipment? I have S71667 which also shipped Dec. 1948.
In the article that Roy wrote about the Registered Magnums many years ago now (for the SWCA Journal), he gives the production figures for the .357 up to and including 1950. According to that, Nov. and Dec. 1948 were the busiest months with 80 shipped out of a total of 142 produced from 1946 to 1949.
That section in "History of Smith & Wesson" that refers to postwar production is, I think, ambiguous and I wonder if that date quoted should be Dec. 16, 1949 (rather than 1948) because Roy follows with a description of what is obviously the Model of 1950.
Regards,
Frank S. SWCA2052.