What happens when a brass spark plug nut falls into the rear spark plug hole. It's all gotta come apart. You can see it sitting under the rear exhaust valve.
When I was putting it back together, two of the head bolt holes stripped and I had to take it right back apart. :/
Ha! been there, done that. The first time i was lucky enough to fish it out silly grabber tool. The second time it was part of a TDC dial and it wedged in requiring head removal.
Very cool bike, hope you get to put on some serious miles.