No help here but it's a cool find! It's not the 15 clone I expected to see. Very unique design.
Some Japanese manufacturers of the time would make any machine for anyone if they had the money for the order.
Many of the Japanese machines had US made motors. I suspect the machines were built and shipped without motors then the importer would add the appropriate motor for their country. Even though it's not the same color, it could be the original motor.
Rodney