It has been reported that Sam Owen who owned Fleetform also worked for Trailcar and designed boats for Dunphy (the X-55) and also perhaps Glass Magic. In 1958, Carlton H. Foster was president of the company. He also served as vice president of Speedway Marine Corp., which originally was a division of Dunphy Boat Corp. Besides the Speedway Trailers, the Speedway Marine built and sold the Magic Carpet spring-cushion boat seat. This was advertised as having been developed with General Tire & Rubber Co. of Akron, Ohio. It was included in Dunphy advertising and in boat models for 1958.
Robert F. Smith of the Chicago area and his brother owned a marine dealership (Smith Marine) in the Berwyn area in the 1960s. They along with their father purchased Dunphy Boat Corp. of Oshkosh, WI in 1963 and quickly drove it into the ground.