I'm sure the person selling the car just entered that number for no reason, and I am 110 percent sure that car does not have 10 million miles. 1 million for a car of that vintage is <i>really</i> pushing it, but 10 million? Nah, wouldn't happen.
The wheel wells must have had new sheet metal welded in them a few times. All the stuff sprayed at them over the years on the road would have weakened the metal considerably.
I don't think its possible even for the most well-built car ever to travel 10 million miles without at least a major structural rebuild to combat metal fatigue and corrosion/erosion.