91-99
1992-1994
77-88
Started in 1983
@ 1956
1958-99 or so
82-88
@1971
You have to look them up in the Standard Catalog of Smith and Wesson by Supica and Nahas or call S&W.
1950-1969 for exact information, it is worth the price to get a factory letter from Smith & Wesson
Your serial number dates your Smith and Wesson model 59 to the years 1977-1978.
1952 give or take
Mid to late 60s