The factory mounted the step fully below the body with a foam strip (F2TZ16536B) between them to protect the paint & prevent noise. The front end is straight & flat under the fender. The Bronco back end curls up slightly into the wheel arch. F-series back ends are flat and curl around under the back of the cab with an integral (glued-on) steel tab.
Note the extra body line at the bottom of the door indicating this is a revised door with a side impact beam.
This would probably be a good addition to the steps, if you can still find a set:
If not, the universal set is reasonably good:
