I decided to mount the main and endurance bus fuse blocks on the left side of the subpanel, just behind where the pilot's displays will go. Access to the wiring should be pretty easy after removing one or more glass displays to gain access. Or, I will always be able to go the more uncomfortable route, up from the floor while lying on my back getting poked in the ribs by the fuel selector.
The essential bus diode (with hefty heatsink) is mounted to the other side of the subpanel. I tried to plan its location so that some of the screws used to mount it can also be used to attach adel clamps.
Mary came down to play Bejeweled on her phone and drink wine and watch me work. She composed and photographed this artful scene while I was preoccupied:
Would the isopropyl alcohol in the background count as a dry white? And which do you serve with pneumatic tools, anyway?