Various thoughts and travels
With the truck & water tank in a trailer out back I'd wonder if it wasn't repurposed?Of course seeing a photo & actually being there are two very different things.
It is likely being used for storage.
I saw it a few years ago and I think you are right.
It almost looks as though it's sinking into the ground. Wonder if it was moved there and no basement/foundation was created beneath it.
A shame it is fading into dust...