Hey Hope..
Back in the 50's and 60's..there was this outfit in Raleigh, North Carolina by the name of "Benson Gyrocopter" that sold kits and assembled models of essentially the same thing as this guy in Texas supposedly "invented". The only real difference was that the rotors didn't fold-up..and they didn't advertise them as being drivable on roads.
As a teenager back then..my folks wouldn't let me build anything that "flew" from a kit..and I certainly didn't have the money to buy anything pre-built. But I remember getting all the plans, etc., to build one! Seems to me also..that I saw the Benson Gyrocopters still advertised a few years back (maybe they're still making/selling them?).
Maybe some of the other older brothers (sisters too) here..remember these? Anyway..thanks for the reminder.
Ichi