The panel itself on the pilot's side is flat. I went with a two part panel for the reasons you mention. I would have preferred the monolithic panel. We kept the radio stack the sameAfter looking at how Cessna did this in the M/N series airframe, it seemed a better way to go. My original plan was to re-work or make an appropriate angle bracket to mount the new Dynon pilot side panel to the top of the circuit breaker panel. The IA disagreed. He and the sheet metal guy agreed that we could safely take the bend out of the circuit panel. This created a new series of problem with fit of the HDX1100 on the Dynon supplied tray. It helped the forward obstacle clearances for connections to the Dynon instruments, mainly the defroster vent assembly. If you look at the Cessna Parts Manual, 182 Parts Manual (62-73 Annotated) page 402 of 722, for mine, with some twists, you get an idea of how Cessna planned and built the panel. It looks like the breaker/switch panel is not structural and is placed with flush rivets mounting to the stationary panel.
The second problem it created was clearance with the supporting structure for the aft portion of the yoke. This attaches forward at the firewall, and contains integral support for both the aileron cables/pulleys and the elevator cables. We decided messing with this is a bad idea. So we had to make clearance. I solved this by trimming the Dynon supplied instrument mounting tray in the upper left corner which provided clearance with the stationary panel. I also trimmed the bottom stiffener significantly where it straddled the control yoke structures. Dynon and the IA and sheet metal A&P all agreed with this.
The third problem created was clearance issues with the aft (pilot side) yoke support structure which attached to the original instrument mount panel with six #8-32 screws and supported the yoke bushing and strut at the pilot position of the yoke. Since there was now a 1/4" offset, we fabricated a spacer for the Yoke bushing to ensure solid interface between the panel, the yoke bushing assembly and the yoke strut. A second spacer set was created for the right side at the radio rail which provided a rock solid mount to the offset portion of the panel. I also replaced the 50+ year old yoke bushing. Now the yoke motion feels much better. In looking at this problem, I also noted a number of radio shop bonuses like RG-58 and leads resting on control cables. These were all re-routed away from controls and are now much better secured and every single wire that could be moved was labeled with BEE2 shrink labels was labeled on each end. We did not drill a single new hole in the stationary panel and replaced the worn or broken plate nuts with new, fresh MS21075 (or whatever the originals were) replacements. We used these to give make it easier to R&R the Dynon panel.
The end result was a much cleaner installation. I've attached the pertinent Cessna PM I used for the analysis and design. There is a Cessna 182 stationary panel replacement STC but it looks like you'd have to take half the airplane apart to use it and that's not something I'm excited to do in a 60 year old airplane.
I haven't started on the right side yet, mainly because the airplane and its pilot needs to fly for a bit. In scouting out the right side, I've noticed that Cessna mounted a mounting plate under the panel midway between the firewall and the stationary panel which seems to me to be an ideal place to re-mount the EMS-220 which will replace the EI CGR30 for instruments and the ship's tach. This will permit the Dynon EGT/CGT, Carb Temp, OT/OP and fuel flow sensor harnesses to stay on the right side at the present instrumentation firewall penetration saving a massive amount of cross cockpit wiring in very limited space and replacing it with a single skyview network cable. Once the EMS is relocated and fully connected, I can remove the CGR30, the ship's fuel gauges, ammeter and tachometer freeing up that space for the secondary ADAHRS and the HDX800 planned for that space. We are not planning to change the angle on the copilot side but will mount to the existing sheet metal, removing only material to accommodate the new instrumentation.
That is the plan. We will see what really happens.