In 1952 a small Long Island company called Helicopters for Industry issued at least four models: Hiller Hornet, Piasecki H-21, Sikorsky S-55, and Piasecki H-25A. Aurora Plastics, also of Long Island, bought Helicopters for Industry's molds and began reissuing them in 1956 under the Aurora label. But when Aurora brought out its line of copters there was also a Kaman HOK.
The questions is: Did Aurora buy the HOK tooling from H for I? Or was the HOK a new mold produced by Aurora? Has anyone ever seen a HOK in a Helicopters for Industry box?