The rear bumper was started this week. Turns out you cannot buy the "Cyprus" bumper step bad for White Pearl Metallic 2nd Generation Ford Explorers (Code WF) nor bumper face bars - non-chrome with park assist cut outs.
Fortunately since the truck has been garage kept, the bumper step pad came off with no issues and the rust from the grit getting under the step pad seems mainly to be surface.
Photos
2nd Generation Ford Explorer Rear Bumper Removal for restore