Schlepped it all back out to the truck for a test fit. Have some tweaks to make but overall I'm happy.
View from inside. The lower left opening will get a plywood panel and a 6" access door to reach the battery from inside.
From outside door, fridge, water, champ chairs, and battery all accessible.
Happy that fridge ended up a little in and down and now the door opens all the way.
With the overall height trimmed down we still have good visibility out the drivers side middle window:
Nice cubby at the bottom of the driver's seat. I have my eye on a solar blanket that may end up here. Or our camp table would stow there nicely. Or spare shoes.
Switches will mount in the middle on the top so I can get to them from inside or outside the truck.
My fan was a casualty - I have a 8" 12v boat fan to mount and thought it could also mount on the cabinet but it blocks my rearview too much. It'll go back to where I had originally thought - in the rear drivers side corner. I'll have to modify the bed frame to add something to mount it to.
I made a few notes and marks and buttened everything up - too hot out there!