The flat box 19mm was introduced in 1976 and still in use in new tool kits. The early kits that used it were the cb400T,Mr175 and the cj360T motorcycles. 8x12, 10x14, 17x19 are three wrenches that are from the standard kit of a 68-71 cb350, 69-71 cb750 etc. there is some overlap in tool kits between 1971-1972 and what came in the bike. So your three wrenches would be good until 1972 on those models. The 10x14 and 17x19 would be correct for almost all Honda motorcycles above 150cc from 1961-1967. As these two wrenches were standard issue for almost all the larger bikes.
Thanks,
Kirk