Had a quick check over the V50 as I can now take her up for her MOT, and tomorrow looks a decent day.
Bloody oil drip is back!
Looks like it's the bottom of the front engine cover that's leaking, not the sump after all: it's hard to see for sure as the fins confuse what you can see, and the gaskets for the cover & sump are pretty much in the same place.
Front cover comes off with the engine in place, it's just a bit fiddly as the alternator cover has to come off, then the stator needs persuaded off the crankshaft before the 12 bolts holding the cover on are dealt with & you're into the timing chain.
The ignition pickups are bolted to the cover and they still show the legacy of the dodgy wiring this bike came to me with:
I did repair this a little, but there's just not enough free wire to do much with one of them so I think this is something to replace this autumn as Gutsibits have a few sets on the 2nd hand shelf.
Everything's back together again but it's too late to check she fires up OK.