Mocking up the Centerdoor wood structure

The Summer of 2026 begins in earnest. The preliminary mock-up of the wooden skeleton structure of my 1922 Centerdoor. This is a painstaking work in progress, with many revisions and corrections to encounter. When it's completed, the sheet metal panels should be able to be fastened to the woodwork with nails.

Taking into account that the firewall and cowl have already been placed, we will start with the Pillar Coupe and Hinge Pillar for the driver's side of the car.

The Pillar Coupe fits into a notch located at the front of the body sill. The Hinge Pillar is placed along with the window header and belt rail at the same time. The pillar couple has the front bottom windshield footer (header) placed as well. Nothing is permanent yet. Lots of fiddling will need to happen to make sure these pieces are in the correct locations.

The passenger side is fitted the same way.

The Rocker Panels are fitted immediately behind the hinge pillars, sandwiched between the hinge pillars and the Latch Pillars. The rockers are a fixed dimension and cannot be altered. Between the two pillars at the curve of the rockers is just shy of 20 inches in length.

As you can see in the above photo, this immediately locates the position of the latch pillars. Again this is a fixed measurement and cannot be altered. Nothing is permanent yet. The passenger side is exactly the same. The rocker panels will need to have their bottom edge sanded down to match the bottom of the body sills as they fall a little proud of the sill.

Next, the latch pillars are located. This will also serve to locate the rear passenger seat box. The rear seat Heel Board is screwed to a cleat that is screwed to each latch pillar. The rear quarter glass sash board is not screwed on in this picture because I am trying to fix a spacing problem I encountered in an earlier post concerning the seat box. However, that sash is screwed in BEFORE the cleat, as the sash screw is hidden by the cleat. Once again, the passenger side is the same. The heel board in this photo is new wood, but I reverted back to the original board that is broken for the time being until I figure out my problem. I may just graft a new section to the broken area and ultimately use it instead.

I took a small break from pillar placement and decided to insert the instrument panel board. This was a feat in itself, as technically this should be done without the cowl on the body. There are two mounting bolts that go into brackets located on the pillars coupe that hold the instrument board to the bottom of the windshield frame and have nuts on the backside of the panel very close to the cowl interior. Then, a metal cover is screwed to this board to make it nice and neat. This is a fixed position. The metal cover has a lip that fits into a corresponding slot on the windshield frame cover. (inside the car)

We now progress to the rear quarter section of the car. There are two pillars bolted to the rear of the seat box top, with brackets that accept the rods for the fenders to bolt to. The rods are supposed to be removable from the brackets, but at this time, only one is able to be removed.

You'll notice my hat in the photo. The tent garage I work in is hotter that nine Hells, so I'm only able to work on the car for about an hour or so at a time. I am DRENCHED every time I work on it.

One final mock-up is the driver seat. This too, is complicated as the gas tank sits under the driver's seat. On the earliest of Centerdoors, the gas tank was under the rear seat, but was soon moved forward.

The seat box for the driver is placed at a fixed location in the car. The backrest should fall in the center of the door opening. One mistake that I cannot correct that was done by a previous owner, is the location of the body mounting bracket that sits under this box. The bracket is slotted into the bottom of the body sill and held on by two bolts with nuts, one on each end, with the main body bolt in the center. You can see a hole plugged up on the sill. This is where the body bracket bolt for the sill should be located. This seat box cannot be permanently mounted UNTIL the hinge pillar location is finalized. The mounting bracket for the pillar is under the side of the seat box (gas tank surround).

Something that I have alluded to and researched is that the interior of the car was upholstered BEFORE the car was painted and the roof was the last wooden structure to go on the car. I am also starting to believe that certain sections of the car were upholstered before some body panels were nailed on OR the floor was installed OR certain items installed (like seats). The interior cowl section had upholstery between the pillar coupe and the interior cowl/firewall/floor board sections. This would have been virtually impossible to do if the seats or front quarter panels had been installed first. People were smaller back then, but not that small.

What are your thoughts? Here's a picture of a Centerdoor being painted and you can see the interior is already in the car.

More to come.....much more