Well it looks like I've found the reason why I was getting a horrible clunking when the engine was running.



Thats looking up through the rear engine support towards the front prop-shaft joint. Yes there should be a rubber donut in there, not a black mess of mangled rubber.
There is no actual donut left in there so the prop is being driven purely by the meshing of the bolts

Just one more thing to add to the shopping list.