Disregard.... thought this was a Marlin in question
Serial Number Prefix(s)
1946-C, 1947-D, 1948-E, 1949-F, 1950-G, 1951-H, 1952-J, 1953-K,
1954-L, 1955-M, 1956-N, 1957-P, 1958-R, 1959-S, 1960-T, 1961-U,
1962-V, 1963-W, 1964-Y, Z, 1965-AA, 1966-AB, 1967-AC, 1968-AD, 68,
1969-69, 1970-70, 1971-71, 1972-72
Starting in 1973, the year of manufacture can be determined by subtracting the first two digits of the serial number from 100: Example: SN 2512345 would have been made in 1975 [100 - 25 = 75].
Here's a Marlin chronology that might be of interest to you: