Research suggests these are historic F1 replicas, potentially used for promotional purposes, and they were uncovered in a small village in France.
The cars uncovered included examples from a number of manufacturers, such as a 1995 Benetton (pictured top of article).
Other rumours suggest they are practice vehicles with low-power engines, but we suspect the story of them being replicas is more likely.
At any rate, seeing them in this condition is heart-breaking. It would appear that some of them have even been smoke damaged.
Running or not, replica or not, I still want one as the centerpiece in my (non-existent) mansion's foyer.
If anyone has more information on these, we would love to hear about it!