Hi John,
Usually there is oil coming out of the bottom of the crankcase from a small vent hole under the flywheel housing, or the brass cover on the bottom of the (in my case three speed) gearbox. What colour is the oil?, if engine oil it's usually blackish, of if very clean it's coming from the gearbox. In theory the black engine oil seeping through the rear crank seal should only run down the back of the flywheel exiting through the vent hole and not get on the clutch linings - but it does, somehow. Or it did on my chummy causing smoke smell and slipping. If engine oil the choice is, engine out job, or the time honoured bodge of chucking into the clutch a handful of Fullers Earth, remember that one?
Peter.

Location: Truro(ish)