got the swing arm installed but only enough room for one washer on one side
I am guessing that is why there were rubber ones?
as for making sure the two sprockets line up the only other thing I can see is to shim the sprocket over
here it is where it is always bolted (nuts and washers removed and bolts slid back)
you can see that the chain isn't quite in line
here is where the sprocket has to sit to be in full line with the front
spacer ? (2 piece preferably )