Converting E body seats to A body

I have a pair of 70 Challenger bucket seats (I believe) that I plan to recover. They are missing the hinge covers and release buttons. Can I simply buy Dart covers and hinge buttons or is there more to it than that? I am not sure if the seat backs are the same between the 70 Dart and Challenger...perhaps its all the same? I see new hinge covers are unobtainium. Thanks