My KE30 is not going off the road, unless it's cancer gets so bad, I have to bury it. As for gearbox issues, there is a very simple solution, that I envisage accomplishing.
Simply leave the gearbox stuck, permanently in top gear, & then develop the engine, so that it has so much HP, that you never have to have change gear again. You'll always be able to reface clutch plates !
https://www.youtube.com/watch?v=dKGiQgxgVzg
Cheers Banjo