Cheers Kurt, that would explain why you see mostly/exclusively 01BFM1/M2 for 70 Camaro which was a late comer amongst the 70 model Chevy's, though the schematic does quote 01FFM1 as well, but I'm yet to see one in the flesh.
So I guess that FPK for 68 is FP = fm pushbutton and K = fader, even though the fader was optional [part of U80] at least for 68 Camaro.