you can replace the entire clutch with one from a cobra or KTM. for KTM get one from a 2000. any of the cobra 3 shoes should work but the shoes are a bit wider so they won't wear evenly. you can upgrage the clutch drum but they are getting hard to find. You could also use the R&D dominator clutch.
did you just break a bolt in yours or is it cracked?
just found it broken in the hub. I was able to drill it out and it seems to be holding. Just broke the flex hose that connects the carb to the air box though. That one might be a bit harder to fix or replace. Just so old it was brittle and broke right in the middle.