You need to provide a serial number.
Since 1972.
Your Smith and Wesson model 19 was made in the year 1978 by the serial number that you have supplied.
1974
1980
1960
With the serial number that you have supplied,your Smith and Wesson model 66-1 was made in the year 1981.
1982
1974
@1972
@ 61
1958
1967