open the cylinder, and it should be stamped there along with the serial number
You can not determine the exact model with just a serial number.
Experience, features, reference books.
Check the butt.
1980
No such serial number in Smith and Wesson data.
Call S&W or acquire a copy of the Standard Catalog of Smith and Wesson, 3rd edition
1980
1974
You will have to find a copy of The Standard Catalog of Smith and Wesson and check each model number.
Read the one on the butt.
@1969
Look on the butt of the revolver.