I seem to see 4 Woodruff keyways on the side of the shaft that is visible, which probably explains why you would rather fix the old shaft than turn up a new one. Not sure what has been going on near the right hand end of the shaft - surely it can't have been eroded away to that extent, unless something awful has happened (like tearing out a keyway)? Also, I'm not clear how your bushing-the-gears idea would work if the gears need to slide on Woodruff keys. Looks like we need more information, unless you have just posted this material for general interest.
