This should be the bearing many people talk about:
Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists
Being that the tip of the shaft is there for support and not integral to transferring torque, I think a pressed on bush to bring the tip diameter up to size and cut/ground true would be just fine. Tig it at the tip to keep it coming off, and it should be golden. Obviously the smaller diameter of the tip never caused a failure in it's previous application, and so there shouldn't be a need to make a whole new input shaft or source a replacement.
That said, a new input would definitely be the best route to go, but that's if time and money are of no concern I suppose.
