I hope... (cautiously optimistic)
It's a GN400 engine, luckily with a complete wiring loom since it differs from the SP370 (no points for example). The first thing I'm going to do is put it in the bike (already done most of that), hook up the existing wiring loom and see if it runs. If it does I'll just leave it like that for a while and see how it performs. Finishing/thinning the wiring loom/painting the engine can all be done later.