'75 rear bumperettes -what fits?

If the contours on the rear are wrong, they may be off of a Swinger. Dart Sport and Duster contours are the same. Just the style and probably mounting configuration changed based on year. But now I am curious about any differences between '74 & '75. The style of bumperette changed (fat to skinny), but I don't think anything else did if they had "shock absorber" brackets to the frame.
Hmmm,
double checked. Info I got actually just says Dart. Will try to verify if Sport or not