The reproduction panels are as Brad posted, simply paper board aka; cardboard.
This was the same material that was used in the headliner. The original side panels
were made from upholstery grade water proof panel board, which was embossed
with a leather grain pattern and painted. Panel board usually comes around 1/8” inch
thickness (.100”) and would fit in the trim ring of an AD truck side panel.
Treated waterproof panel board is still used in automotive applications and is
available from upholstery suppliers such as this:
http://www.perfectfit.com/15347/154...Black-Treated-Waterproof-Panelboard.html Simulated leather grain book covering can be found at book binding supply companies.
This is some with a heavy leather grain that I’ve used to restore hard cover radio schematic
books (Riders & Sams):
http://www.pbase.com/dennygraham/image/162229367This is Navy Blue but is made in many colors and patterns. This particular material is
.015” thick and could be applied to a panel board with glue using a roller or a vacuum bag.
The total nominal thickness would still be under 1/8” and should fit in the U-channel trim
rings on our AD’s.
Denny Graham
Sandwich, IL