I'll play Devils Advocate here....
Wouldn't it have to be an SS car to be an original big block car?
Rear wheel wells have been modified.
Hood has a kink at the hinges.
Right front bumper is pushed in under the head lights.
That is just a quick observation, but the rear quarters should be checked out pretty thorough, IMO.
For the price, I think you are getting some nice metal, but I'd make sure that you are getting what the seller claims. I have been known to make some inpulse buys and wished that someone would have been an extra set of eyes for me.
Good luck!
Randy