Oh joy, today the crank pulley broke and took out the dust seal and showered metal fragments into the timing case cover on the Land Rover.
It seems it had be disintegrating for a while, but it showed no outward signs until the failure today.
When I stripped it down, it's bloody luck the metal didn't break the cam belt. The woodruff key is shagged, but it looks as if the crank is ok. The timing case cover has been badly affected, and sourcing a new one of these could be difficult.
I have spent the afternoon at Brookwells buying all the new parts and belts I need to fix it up; total cost £120! I still have to get the crank cog off the crankshaft, and I will post up the photos of how I do that later this week, but in the meantime, have a look at these photos of the damage.