wanttaja
En-Route
In some cases, those building from plans couldn't show the required documentation. One can download the plans for some types (like the Fly Baby) for free.While it's true that anyone could make up a serial number, if on request, they can not produce any documentation that an aircraft is being built, they lose their reservation and any money paid in. Another possible add-on is to limit the number of reservations that a non-manufacture can reserve to a small number. Maybe 5. Not sure why person or business would need to reserve more than 5 N-numbers.
In 1998, there were over a thousand Bensen Gyrocopters in the US registry. There were more Bensens than any model of RV (most-common was the RV-4, with ~800 listed).
Today, that fleet of Bensens has been whittled down to just 47 aircraft (compared to over 900 RV-4s, which aren't the most common model anymore). This is mostly due to the FAA re-registration process started in 2010.
Now, I don't think there are a thousand scrapped Gyrocopters out there. I'm guessing the first step in the building manual was "Obtain a registration number from the FAA...."
Ron Wanttaja