Nice Ironhead did you solve the clutch issue ?, I can see that over the years its become a XLCH that started life as a XLH , and that clutch pressure plate is off an early model ? with the extra holes where small studs would of been , so you need to check as their are three different spacer sleeve sizes for ironheads , make sure you have the correct length spacer tubes ? are the early pressure plates the same thickness?
because seeing that early pressure plate on the 77 and reading about your clutch woes something is not adding up here , I have a 74 xlh with a mustang tank like you brought your bike with , their not very common , quite hard to get , enjoyed your blog cheers