You've gone through alot of it already, why not finish it out right and keep it?
You say you have a good mower, so the 123 isn't a main machine, could be a back up? If it was my choice I would spend the time and fix it into a dependable tractor. Take your time, as you get extra $ put it into the 123. It's not eating any oats!
Pictures would be a plus.
