Plastic interior pieces

I know this is a newb question that will likely be met only with "google" as a response, but I have honestly looked through google, and multiple car parts shops from a mopar magazine I have, and still, I cannot find these pieces. I'm not even sure what they're called to search for them.

I have a 74 Plymouth Duster. I am looking for the plastic interior parts, like the ones on the tops of the door panels, the ones that cover inside of the A pillar, around the inside of the top of the car, etc. They're cracked up and need replacing, but for the life of me, I can't find them. Sorry. Still new at this.