Vaporware...very clever.
No doubt you're probably correct but then what if you're wrong. What if this thing is for real? Watching out for it costs both of us nothing, as long as we're not the first two in line to buy it!
Hello there old-timer. This was in the 1960s or 70s. I saw several documents on it. It was a scam from beginning to end. The con-men who came up with it also claimed they were building a car based on the "Nobel Gas" (yes, that was the correct spelling) engine. I believe the actual name was [sic] "Nobel Gas Thermonuclear Engine" and the car was called the "Aerocar" or something similar. They were taking deposits for the "coming soon" car, and as I recall a couple hundred people gave them deposits.
A colleague of mine worked for Lockheed at the time and they got conned enough to send him to inspect the "working prototype". The inventors had scheduled a big show for their "engine". There was a huge explosion, probably conventional explosives. As I recall, nobody was injured. That was the end of the car and its "engine".
=======================
The U.S. Patent office stopped requiring working models circa 1976. The reason given: not enough warehouse space to store all the prototypes. Ever since then, it has been possible to obtain a patent on anything, no matter how crazy.
--Boris