You’ll be looking for the ‘hardboard’ type headliner that appeared starting in 1973. Prior to 73 it was soft (flexible) with bows headliner.
I’m not sure if the exact hardboard material is reproduced now as the original is cardboard type with a paper colour covering on it. My 75 headliner has a couple of more gouges on it where that paper covering is ripped/torn. I believe the repo headliners are actually plastic now.