Seat Rail Identification Help Request

[JoesEdge]

Quick background, I bought this 1974 Duster recently (couple weeks ago - new to MOPAR vehicles too) and I'm starting to tear down the inside.

The car was setup for drag racing, so it had plastic racing seats and and a tiny Grant steering wheel (that's for another thread).

Anyway, can anyone tell me if rails in the attached images are aftermarket rails or factory rails?

Thanks!!!

 

[JoesEdge]

Here's a couple of pictures of the seats in the car. My goal is to go to factory bucket seats or keep it original with factory split bench seats at the Fender Tag suggests.