Cars with Sidemounts

[Bud]

I recently saw a vehicle with dual sidemounts, but there were no holes behind the rumble seat area for the typical rear mounted spare tire bracket. There was no hole in the sheet metal panel below the deck lid and there were no holes in the bottom sill.
Were cars that came from the factory with dual sidemounts set up with special panels and sills that had no holes? Or is it more likely that this car was restored this way?
I am under the impression that there were special plugs that screwed into the tapped holes for the rear mounted spare tire bracket. Is that what it should have looked like?