I managed to clean up the engine and try and run it. Yes, it IS green (or was green... seems that someone painted the cylinder muff and spinner red, it came off in the cleaner).

It will start and run off a prime but not carry on. As soon as it warms up it wont fire and all compression is lost. I think its worn beyond practical use. I will try later on tomachine a new cast iron piston, and see if I can restore it to running condition.

AJC