Around 1984, but you will need to check with S&W for a more precise answer.
No such sn with a S prefix. You will have to call S&W.
1980
No serial number provided.
No serial number provided.
No serial number = no way to answer.
Need the serial number
No serial number provided.
K 7981 smith&wesson
You will need to add the model of Smith and Wesson to your serial number to get the correct year of manufacture.
1978
y
THA7110