A couple of other observations. The front and rear mounts use larger tha standard studs and the cylinder is made from something quite different than the rest of the engine. Even looks like steel but it’s not magnetic. Also no white wire out of the magneto. Exhaust port is very rectangular and the intake is the size of the ones on the 66/80cc motors.
Some of the 4L tanks are 12m x1.0... the repop Cruzzer tank is 14m female threads... Maybe something with the new stuff coming out... Honda hobbit is 12m with a clear sediment bowl...The other thing I jus noticed is that the fuel tank has threads on the outside of the fuel valve connector instead of inside.