Well it was bugging me that I couldn’t find it as I remember taking it off and it could only be in a couple of places. So I once again pulled everything apart. To no avail.
Then I thought, “I didn’t throw them in the rust remover solution and leave them in there did I?”
Bingo
So thank you everyone and for future reference for anyone looking for one...
Indeed it’s 1-1/8 across the flats. 3/4 coarse pitch (16?) thread. One side flat and one chamfered. Thickness is 0.317 on mine.
Lock washer is a simple split lock washer. 3/4 ID, 1-1/8” OD and 1/16” thick.
