The pictures are awesome. That bike might be too nice to ride.
This is a picture of the eccentrics and the plastic bushings, to show how they don't match in length.
Shercoman's advice is probably spot on and the plastic bushing should fully support the eccentric. However, his conjecture that Yamaha had planned obsolescence in mind for the BWs is patently ridiculous. We all know that the BigWheel is too far ahead of it's time to ever be obsolete. Right? Yeah, totally.
My personal theory is that the brilliant Yamaha engineers wanted a pocket of grease that would be transported by the the spiral channel in the plastic bushing to keep the eccentric properly lubricated. They were brilliant. Positively brilliant.