It was just a bit of luck that I ran into him really. He pulled into the car park by the beach on a magnificent Honda CL360 and parked next to my bike, then sat on a bench watching the sea. I went over to chat and eventually asked if he'd done up his bike himself, which indeed he had. So naturally I asked for some advice and it might just save me a lot of work getting the bike started. The man had two things to recommend.
First, get a bike which still has good chrome - honestly much too late for that for mine. Secondly, and more important, the first step he takes when restoring a bike is to get the engine running. Put some petrol in the tank and give it a kick. Does it work? All good then. Old Honda engines are reliable, and my cub's only has 5600 miles on it.
I can't stop thinking how lucky I was to chance across him before I dismantled the whole engine. I had been worrying for a while that I would do more damage than good anyway. So for now I'm not going to touch it, aside from cleaning off all the old dirt from the outside.