Blue Sky,
I have an announcement letter from the Buck Knives' Director of Marketing and Sales dated July 1, 1982 that announces the new fingergrooved versions of the 110 and 112. The curious thing about this is that the two fingergrooved knives are not featured in the 1983 Buck catalog! Instead, they are finally introduced in the 1984 catalog. I will surmise that something went awry and Buck found it necessary to delay the actual introduction.
I can tell you that 4 dot versions are the earliest regular factory production 110s and 112s but I have heard rumors of "employee specials" that were fingergrooved earlier than the 4 dot era. The four dots were first available sometime in 1981 (approx.) so that should help you get a chronological setting on them.
I also have a very early prototype fingergroove 112 that I obtained from a former Buck sales representative and it also has a four dot blade. This prototype has obviously deeper grooves than the standard fingergrooved knives.
I hope this helps a bit.