I went thru a scenario very similar to this when a friend of mine was hit going thru an intersection when a young kid ran a red light and hit him just behind the driver side door. He was having a bad time dealing with kids insurance company with the claim so he asked if my shop (as the repair shop) would handle the situation with the other drivers insurance company which I did. The insurance company searched high and low for a convertible quarter panel for his car and only could find the converted hard top quarters that are available from Ken Hopperdietzel which are really nice, problem is, the kid hit a real 440-6bbl four speed shaker convertible Cuda that deserves original parts . After a little negotiation, the insurance company realized how high the claim could have gone if he would have sued for "diminished value", the claimed was settled at more than 5 times the original estimate.