I remember reading or hearing somewhere that the GG designed their bikes so engine internals were all Honda parts. Piston, rings, pins......and the entire clutch assembly.
I know that a KX 94-96 rear fender, airfilter, side panels will fit my 99 EC200. I have head the engine was a very close copy of the CR250, but in terms of which parts will interchange, I'm not sure. Give Jim Cook a call at Smackover Motorsports.