Hi grumpy, unfortunately the records of a lot of board decisions have been lost in the mists of time...you may well be right, but in all events, Briggs seem to have appeared on the scene with SB with the release of the Model 430 Diplomat in 1976 which sported a 2.5 HP model.
Prior to that, Kirby-Tecumseh had powered the later Model 33 with the 2.5HP HK25 and of course the first SB 45's with the HK30 3HP engines back in 1968.
