1948-9. You will have to call S&W to narrow it down more.
@1969
1977
No serial number given = no answer.
1969
1979
You must call S&W
1986
80-81
You will have to call S&W
You must call S&W
You will have to call S&W for the date.
Call S&W with the serial number and they will tell you.