I still have parts. Get a list and let me know when your ready.
SMOKIN score on those gensets!
Edit, I have found that if you can get one of the OLD wrenches, that has a LOT of meat around the open end, they are stronger than the current manufacture line wrenches. Also! I have found that keeping even pressure on a wrench and tapping it with a small 6oz hammer with knock the rust loose. You might have to tap it 30-50 times, but it WILL work.
It has been explained to me like how a hammer drill works. The small taps work wonders. I have done this with 5tons, deuces, welders, and MEPs. You might even try a different size hammer as the pitch will change and have a better effect.