My friend just bought this. The seller described it as an experiment by Bub from the 1940's. It has Bub and West Germany on the bottom the chassis - which leads me to think it is from the 1950's, as West Germany did not come into existence until then. In the 40's after the war it was just referred to as the US/British/French Zones.
Does anyone have more info on this? It has a DC motor and still runs well.