One or two?! I have located at least ten that are ‘N’ registered, but not necessarily airworthy.

I said “one or two” flown as warbirds…display aircraft…that are regularly displayed or seen.
The other week I was having one of my vintage cars worked on and in the garage was a pin up-style calendar and it had a scantily-dressed woman leaning up against a rerstored C-1.

There are probably others, but as you note, just because they have a registration dosen’t mean they’re airworthy…or even really exist.