Thanks Arwyn and I think I can track it from there. From what I have seen online there is a clutch fork to hub spring, a clutch fork to pivot spring (probably the one that has gone) and a `D`retaining clip. Could also be that which is gone.
So the plan is to do the rally with whatever dodgy stuff is going on inside that Bell Housing (actually it feels ok) order the parts, and then pull the engine out and see what's really going on.
Burton Power seem to have the bits I will need but I heed your warning about the different clutch arms. Mine is not the most common one that comes up in a google search.
