Headliner swap

We found a guy on ebay that sells new hardboard headliners and sail pannels for a-bodies. We ended up getting a new soft headliner and new clips from year one but have decided to go with the hardboard instead.
Do you still need all the ribs that the soft one hooks to along with the small wires along the top of the rear window or do you just put it in and hold it up with the coat hooks and the rest of the trim?
This is beeing done to our 72 scamp.