The Hobby Helpers plan number shows it was published in December, 1956.
His article from that magazine explains this design is from a series started seven years earlier, one of which, called the Curtis Stunt Champ published in American Modeler, March 1953, and won his age category at the 52 Plymouth Internats. (So the 52 Stunt Champ is OTS eligible and at least one has appeared at VSC by Bob Whitney - a kit has been recently available. A nice performing airplane with flaps.) This Curtis Special was built in the summer of 1955, so is not OTS eligible. Interesting design with swept back wing and tail, trike gear and smallish flaps. For its day, it performed well. Curtis was (is?) a good pilot.
Keith