I cut out a piece of gasket material. It was some stuff I had laying around, about 1mm thick, of cork and rubber.
I did my cover a while back and the quadrant shaft was rusty, seems to be a condensation trap. One other thing, there was a washer (spacer) on the shaft betwixt some of the stack, that I forgot and didn't get friction, till I added the washer.
Had a little trouble with the woodruff key also. Ended up making my own. Found the original after the job was buttoned up.
I think Ol Henry got a buy on 7/16" bolts.