Advice on buying a '75 dart.

I have a 1974 Plymouth Scamp that is light blue. Mine has the same blue steering wheel and steering column, but every part of my interior is also light blue, including metal dashboard and the dash pad. If the interior color was changed, I would check every VIN location on that car. If the metal dash frame was changed instead of painted, it would likely have an incorrect or mis-matched VIN from the rest of the body.
If you can verify the body VIN locations match the dash VIN, then at least the scam part is not much of an issue.
Then it just comes down to checking the body carefully for signs of hidden rust. In the pictures, it looks like the trunk was re-painted to me. I could definitely be wrong, but there is usually a layer of undercoating sprayed onto the inside surface of the quarter panels for sound deadening. It also looks lighter or maybe white in the spare tire well area.
The one picture showing inside the trunk, right side of car, where quarter panel meets the outer wheel house and trunk floor extension, kind of looks like paint has flaked off of rust. That is a common spot for rust.
Realistically, who cares what we think about the price. I would have no problem paying a little more for a solid car, if I can be pretty darn sure it's legitimately solid and dash and body VINs match, even if I thought it has really changed hands several times without title transfers. Ultimately, it's worth what YOU, or someone, is willing to pay for it.

I hope it's a legit car because I do like it. I also always recommend bringing someone with you that knows what to look for. Since they are not excited about the prospect of getting a new toy, they will look more critically at it, which helps in finding hidden rust you may miss.