As us old timers die off more and more of these will come up from estate auctions.
It is very common for people to buy cars and put them up probably some brand new ones out there just have to find them.
I know Jackey Jones Ford does it quite often. Daniel Carpenter bought several Fox body Mustangs from him that he had in warehouse with single digit miles never dealer prepped. He is the one that sold Perkins the Boss 429 that had never been titled or dealer prepped.
He had 17 of the new Cobra Jet factory racers but sold all but one.
When I was talking with Daniel Carpenter about how he found them with no miles he said it is very common for dealers to buy and just put them away.
Here is couple pictures in Carpenters museum. The Ford GT was same also.
That is Daniel with the blue shirt on. All these cars are a tax write off for him. He takes parts off to copy and repo from them. So they cost him nothing, lol.