A Demon with Duster Tail Lights?

I was driving along, going to the grocery store when a guy pulled up next to me in a demon! Wish that happened more often! I asked him if he could pull over and if I could talk to him about his car. He said sure. While i was talking to him I noticed it had 70-71 duster tailights. When I asked him if it was a clone, he said its a real demon and showed me the vin. It was! He said he never modified the tail lights they were always like that. Have you guys ever heard of anything like that? Would it be a car that was used to show off a new model in dealerships? Sorry I couldn't get a picture because I dropped my phone a couple days ago and the camera broke. ):