16.5" long prototype made from Marx's Rocket Racer wind-up race car. Underside of car has hand-painted text reading "#1542 - 12-22-37 - Erie Pa," indicating this prototype was created in 1937 at Marx's Erie, PA. plant. Very similar to the Rocket Racer, this prototype differs in that the dimensional tin litho driver is larger and tin litho cockpit is different. Also, left side of car has had elaborate plated exhaust pipe added w/large chamber towards rear to contain sparking mechanism, which no longer sparks. Built-in key on side works and car moves forward when wound. Scattered all over wear in the form of paint nicks/scratches and aging w/some oxidation along edges. Wheel rims also show moderate wear. Fine. This particular prototype never saw production.