There was a change. I'm still not sure if my bracket "sleeve" is correct but there did appear to be that protrusion there - whether sleeved or originally cast. The parts diagram for the M38 also shows a spring washer (which I don't have) and the thicker boot/seal that I do have in my pic. Those are parts #9 and #10 in the M38 diagram. If I can find a suitable spring washer replacement I think it'll be OK.
I am still a big fan of Walck's, but the "Bell crank kit 7/8" CJ2A, CJ3A, CJ3B, CJ5, CJ6, DJ, FC 150, M38, M38A1 Part Number: 920556" is another part that should not be advertised as completely suitable for the M38.