OOOOOOOOOOH !
The good Major has hit nerve, has my full attention.
1948 S&W MY Birth Year, a bucket list acquisition...

I'm continuedly, on the lookout for my birth year.
K-38 COMBAT MASTERPIECE, pre- Mod. 15
if I were to make it even more of a search, it would be Ordnance marled perhaps Air Corp/Force issued.
Beginning in 1960, the U.S. Air Force began purchasing them, and the only distinction from commercial guns was the stamping of “U.S.A.F.” on the left side of the frame.
So, the likelihood of a Birther and US marked is perhaps a dream fart.
Or perhaps a N Frame from 1948...
The closest I have is my minty M&P pre- mod 10. made in Nov.-Dec 1946- shipped in Jan. 1947.