Thanks to everyone and the Ford Body and Ford Ch***is books I'm down to just this one part (at the moment) that I have no idea where it goes. I'll check the main board and the Barn as well. TIA
It goes inside the rear fender to protect the gas fill tube, spot welded to the floor from underneath.
Rustvelle You nailed it. Many thanks. I would have never figured it out. Just came up from the shop after test fitting it. Fit like a glove.