Call S&W and they will tell you. Buy the Standard Catalog of Smith and Wesson, 3rd ed by Supica and Nahas and look it up.
1973
@ 1978
No sn provided.
1980
smith and Wesson (smith & Wesson) and Sig-Sauer
1971 sales@countrygunsmith.net
Early 80's.
I purchased a used Smith & Wesson 4013 for $350.00
You must call S&W to find out.
Smith and Wesson 500
Call S&W and they will tell you when it left the factory.
The Model 57/657