The bush was ok for size with my layshaft ( lucky ) anybody putting in a new layshaft would probably need to ream though, have noticed when replacing bushes they do get a tad tighter when instaled.
Have also noticed on both my bykes, it's the end of the layshaft that sits in the bearing that gets ribbed ( for want of a better description ), haven't worked out why this should be.
All the best - Bill