Lots of messing with cables again, though no picture to tell the tale. Basically three sets of cables are wired into D-sub plugs and attached to the panel. These looms and a ram air tube from the Dynon are fed forward through a hole in the firewall.
After pulling the wires I started on attaching the power control units. And spotted a mistake....
The rectifier, part of the engine kit, is bolted to the firewall shelf. However, I had previously installed the nutplates on the top surface rather than the bottom surface. Picture 1. Fortuitiously the holes in the rectifier just fit over the barrels of the nutplate (Picture 2), so I could bolt the unit on, and it sat sweetly on the four rivet tails, with space for air to circulate underneath.
I checked with Vans who said they would be inclined to fix the problem, but it probably wouldn't matter if I didn't. I also checked with Tim, who pointed out that the strength of the attachment was dependent on the four small rivets. A problem for another day...