Thanks for the information guys. I actually decided to take the old part to a machine shop to have the damaged region of the shaft turned down to the deepest groove (~0.100") and a new bushing made to work with the altered diameter. The shaft will turned down to near the area where the rear seal slides. There will be no alterations beyond that point so that the stock rear seal diameter will still work.
However, if this fix doesn't work, I now know where to look. Thanks again. | 
