Originally Posted by davashcow
The part that has failed in my gearbox is no longer available.
Fair enough reason.
FWIW, in Oz, getting a used KBW10 wouldn't be too hard although you might have to wait a couple of weeks for one to turn up but I have no idea what the used market is like in the USA
If you get stuck, I feel confident your old one can be repaired. Most of the parts
should be available at bearing supplies shops but if it is something else, a good machinist can probably make it. If you have to go down that path, start a thread on CF, post some pictures and see what assistance is available here!
In the meanwhile, I hope you find a complete box ready to bolt on.