These model tractors were built by La Roy Unger, N 3084 Loop Rd., Monroe, Wisconsin 53566, using anything he could find around his shop. La Roy has been a farmer all his life and model building is his hobby now that he is retired. The tractors are built of wood, cardboard, metal and plastic. The wheels are plastic sewer pipe turned down in a lathe, the spokes are tooth picks, the hubs are wood, the gears and steering wheels are from old alarm clocks, the engines are balsa wood, the frame channels are wood. The gears on the Caterpillar are from an old egg beater.