Paint or gravel guard.

There is a '74 Duster close to me for sale. Decent price, but the photos appear to show a Ziebart rustproofing job. Rustproofing under the hood on the inner splash shields and anything in the way of the spray gun. The trunk area looks like it was sprayed. Hard to tell with the carpeted trunk liner in place. I can imagine what the undercarriage looks like. The doors and jambs have plenty of little black "buttons". So much for the decent price.

It would of look like mine did .The body shop were not to happy to remove it.lol