You're out of luck purchasing a set because none of the parts vendors support the 9' heavy duty bed as these are very rare birds. The Advance Design 9' bed is quite common by comparison, but it doesn't have inner wheel wells.
Each wheel well is made of four pieces: the wooden arch, the sheet metal side panel, and two short pieces of sheet metal bent like angle-iron at the front and rear.
The wooden arch on my truck is made of white oak, even though the bed boards are pine. The blue truck in your picture is also oak, so I suspect it's original. This is probably because pine has a tendency to split when steam-bent, especially when flat-sawn. These arches are 3-1/4" wide and about 1" thick (best I can tell). They attach to the bed side at the rear and the "half arch" in the front with pan-head wood screws.
The sheet metal side panel looks to be the same thickness as the rest of the bed. It is basically a half circle with a 1" lip bent on the bottom edge. This lip bolts on top of the wooden floor with 1/4" carriage bolts. Along the arch, the panel has drilled and countersunk holes for flat head wood screws to secure it to the oak arch.
The two sheet metal angle brackets are 3-1/4" long and 1" on either side of the bend. Each is secured to the bed floor and the oak arch by four wood screws.
The design of these wheel tubs is really pretty simple, except for the bent wood. If you're not looking to re-create the wood, it would be easy to curve a piece of metal in a slip roll and weld it together. When I get to that point in my truck restoration, I plan to build a form and a steam box to re-create the wooden arch because they're really a unique design feature.
If you need more information or exact measurements, let me know.
Bob
