I saved this photo and information from a past thread. At the time, everyone seemed to agree these corresponding dates and pin patterns were correct. Feel free to make corrections if necessary.
Buck 110 Folding Hunter: 1974-1980
There are overlaps of time for the exact birthdates of most Buck knives from one year to the next, but to lessen some confusion, the following is an accepted rule of thumb for BUCK .110. U.S.A. (2 dot) knives. 110s from this era all have square frames, solid ebony handles, 440C blades, soft grind lines, stainless steel rocker pins and black leather sheaths made in the Buck factory.
1974-1975
2 tiny brass handle pins.
1976
4 small brass handle pins.
1977
3 small brass handle pins.
1978 - 1980
3 large brass handle pins.