You must call S&W with the serial number and ask.
1973
You will have to call S&W and give them the serial number.
Inside the crane area
59-60 yrs old
S and W stands for Smith and Wesson. Mod 15-3 was made sometime in the 1970s and one has a serial number of 5k13xxx. This is a revolver with a four inch barrel that the Air Force used.
61-82. Provide a sn or call S&W with it to narrow it down more.
75-350 or so; 1981
1962-1969. You will have to call S&W to narrow in down any further.
K
You can download or request a manual via mail from the S&W web site
100-400 USD or so
Made by S&W.