At 1:09, Grand Prize Pachinko, I think this was the very first Pachinko machine of this kind by Nishijin. The funny man in the center is in a pachinko parlor and a pachinko parlor being the setting seems to fit a prototype nicely. Plus, its color on the game field matches the color of the controls and that checkered floor he stands on matches the top boarder of the game field. I have 2 machines with those same colored controls and one has that same checkered boarder.