Symptom: oil coming down exterior of sandwich plate between block and bellhousing.
The question is:
Does the sandwhich plate between block and bellhousing go all the way to the shaft such that if there was an oil leak from the rear main bearing seal that it would run down the block side of the plate rather than into the bellhousing? Eventially I suppose if there was no drainage from the block side it would fill up and flow into the bellhousing - I note a drainage hole in the bottom of the bellhousing - no oil from there!
It's been a while since I did the clutch - there didn't appear to be an oil leak from rear seal. So I suspect it's the sump gasket. Nothing from higher up the engine.
One things for sure if the sump comes off it's got to be painted before it's put back on!