I will take the other direction. If looking for a car to restore, and if it is true that the engine has been rebuilt and the mileage is correct as presented, I would consider a drive to look at the car. $3,100 wouldn't be an outrageous price,if everything is there in decent condition.
The engine compartment reminds me of my father's old car that had undercoating sprayed indiscriminately throughout. His car had no rust, but was put into long term storage that way to prevent it along the seams. The floors appear to have surface rust, but that is pretty easy to handle. Mh old TR6 had the carpet glued to the floor, and when removed, the residual glue and carpet resembled these floors. Regardless, I don't really consider surface rust as "rust" on a restoration project. As long as there are no holes. It's hard to tell, but the panels appear to be straight. We can't see a lot of the pieces that are off the car.
Would I buy it? No. I prefer earlier cars. But I wouldn't pass judgement on it from these photos. I've seen cars that photographed much better than this, but were far worse.
I don't think this one is that bad. But I would have to see it in person.