Drilled out the bastard clutch housing bolt that had sheared off. Flywheel off (note the nifty flywheel locking tool courtesy of a house radiator bracket and a bolt and a few nuts plus a grinder), sump off and rocker cover off just so I can replace all gaskets. Just waiting for parts now.
Looks like gearbox is either leaking from the adapter plate or maybe the sensor thingy. New o-rings ordered for the adapter plate.
Oh, and that damn breather filter thingy off the rocker cover. Pipe has well and truly had it. Seems to be 20mm inner diameter but it will have to have a hell of a bend in it. Ideas?