Hello Phil,
I scrapped a 550 a few years ago. It had a cam meltdown. I scrapped the frame, but I kept all the parts....I think. I have just had a rummage and found nearly all the bits for a T reg 550. I have looked at the CMS for a 550F 1976 and the parts pretty much match what is in the parts book.
Have loads of engine parts and a solid tank, etc....PM me if you are interested
Cheers,
Jerry