Many years ago, at a small petrol station in rural Suffolk, I came across a Black Prince or Knight parked at a petrol pump. There was no sign of the owner. The clutch cover was necessarily missing and the clutch had been converted to Lightning spec. However instead of a Ferodo friction disc there was a replica roughly cut from a piece of three-ply plywood and with over extended 'ears'. I waited around for a while in the hope of meeting the owner but he/she didn't show. I have often wondered how this 'modification' worked in practice.
Hugo, can you remember which Suffolk village garage that might have been?
As John Cone says, it's not likely to have been his D or his father-in law's. Regarding home-made friction discs, I recall someone acquired a number of car clutch facings(Austin Seven perhaps) thinking that would be a cheap option. Unfortunately, these lacked the necessary reinforcement around the outer edge. Having patiently cut one these to shape the first attempt at a road test resulted in no drive after the first few yards-a failure that has ocurred in recent times I believe.