I'm inclined to think this is someone's attempt to mildly customize an interior. The seats don't look professionally done, like would be for a show car, but they are better than cheapie seat covers. I'll bet the original seats deteriorated so an owner way back had what we see installed.
The ad shows this car as serial number 2212, it's neighbor, 2211, is in our registry and is also a Copper Dust over Palm Beach Ivory car.
I like the Copper Dust steering wheel. My uncle had a black factory exec 54 that had red leather seats with a maroon dash and steering wheel in it. My cousins practiced their hammering skills on the car so my uncle junked it.