Got home from work to find the nf75 engine I ordered had arrived, a preliminary look at the top end had determined that it wasn't seized but had been killed by idiocy.
The piston had been run back to front and snagged the top ring, it has plenty of wear and carbon on the piston to suggest it had run for a while like that before the ring gave in.
Unfortunately this has caused some damage not so easily repaired, the major problem comes because the cylinder is alloy with a steel liner and the ring jamming has forced the liner downwards slightly (fraction of a mm) but that was enough to crack one of the stud holes in the lh case and has damaged the top and bottom edge of the exhaust port
The lower edge has a pretty big lip that sticks up past the main port casting so might be able to grind it flush and the upper might not be to high as to stop me from raising the port height, the problem I think though will be in getting the liner pushed back up flush so the head surface is flat again although i could probably get away with skimming the top down and running a head gasket as no gasket was fitted originally by the looks of it.
The piston does have a 12mm wrist pin as apposed to the 10mm on a camino/ hobbit but sitting it side by side with a +1mm pa50 piston they are identical height and the rings grooves line up perfectly, I haven't pulled my calipers out to measure the wrist pin centre line yet but they look like they are the same distance from the crown.
I will have to pull my impact driver out to split the crank and measure that up but I don't think it will be usable tbh the mains are rough and the big end feels notchy.
The stator cover is cast aluminium too so will be nice and strong for a pull start conversion.
engine has arrived not usable as is but will be measuring up when I get the time.