RE: Why not a Webra engines thread?
The box says "WEBE 1024 + S", "Speed 61F Aero". It looks like a standard Webra Speed .61 side exhaust with TN2 carb. It does have factory drilled and tapped holes (3mm) in the exhaust stack., but the crankshaft has this 8x1.25 thread shaft. If this was intended to be a special purpose engine, I'd like to know what that special purpose was.
ChiefK