I restored a '65 Galaxy convertible once that was like that. Owner got out at a store, thought he had in park, and it rolled across the parking lot into a tree. The impact knocked the quarters off. The only thing holding the panels on was bondo. Not even rivets.
Some guys out there can be bondo masters. Did a '66 LeSabre convertible once. Found body lines that weren't there when we started. Same thing on a '70 LeMans Sport convertible we did.