Two more pictures of the roll-pin in the old bearing. Is it supposed to be sticking out like this or flush? (Photo: David Bolton)

The inner end of the roll-pin. Part shows obvious signs of wear, but there is a recessed part that doesn't. It's not possible to determine whether the pin projected into a hole in the carbon ring and so has had quite a bit ground off by the boss on the cover plate plus some broken away, or whether the pin only bears on the side of the carbon ring (so holding it slightly off-centre) so very little has been ground away. (Photo: David Bolton)

An NOS AP/Borg&Beck release bearing I've had since 1994, no sign of a roll-pin, protruding or flush.

These four photos by Bob Muenchausen: Badly broken-up bearing but still a ring of carbon seems to be left. Probably once the boss on the cover plate had worn down the carbon to the top of the carrier there was a mis-match that meant it was bearing on the casting rather than the carbon ring, wearing that down instead, note the upper piece of the outer ring of casting is much thinner than the lower piece. Eventually it go so thin it couldn't take the force of the clutch and it broke suddenly, further operations of the clutch pedal pushing the slave piston out of the end of the cylinder. This is very similar to what happened to the clutch on my roadster many years ago (mileage unknown), although on that the offset was worse and towards one of the pivots which snapped off leaving the rest of the bearing relatively undamaged.

Inside of the bell-housing liberally coated with carbon.

Friction plate with the lands worn away but still well clear of the rivets, not bad for 75k

Deep wear groove in the cover-plate, although Bob reports that the flywheel itself was fine. I found much the same on the clutch change I did, perhaps deliberately dissimilar strength metals?