When I drained, a little over 400ml came out.
Oil level checked and adjusted the day before failure (over 200ml added).
Read an interesting post from Dave J regarding blow-by, and I thin that's the ultimate culprit here.
Anyway, to update, I got the engine out, removed the generator cover, removed and checked the oil pump, and made sure the under piston nozzle was clear.
This gave good vision into the bottom of the case, so I could see the debris.
I removed the oil sump cover and sreen filter, and the drain plug, and by jusdiciuos use of a syringe, a turkey baster, a pair of 10" tweezers, and a couple of gallons of cheap-ass oil, I was able to clean,all the debris out, and flush the small particles .
Very pleased I got this done without having to split the cases.
I think I may be able to get some "after" pics to post, which I'll have a go at tonight.