I would suggest you contact Matts Machine Shop in South Wales to get a new belt, they are certainly cheaper than Morgan. Ask about the modification kit for the crankshaft drive pulley, bolt and idlers at the same time. If it doesn't already have it, the front cover should have the gasket removed and spacers fitted to give some cooling airflow, also slots in the front cover. The "snake skin" debris in cam belt case area is the release agent from belt manufacture and is normal. Not seen a "hairy" belt like that before, looks like you may have got it just before failure? With all the mods done, Morgan say the belt life is 30,000 miles.
