Here are the upper side walls of the refrigerator compartment. First the forward/left side (stove wall). Where you see the lighter colored plywood areas is where the white vinyl wallboard (maybe 1/16" thick) was stapled/caulked to the sidewalls and butted/caulked to the outer wall as well.
And the same view but of the rear/right/closet side. Again you can sort of visually extrapolate and see where I have already removed additional sections of the white/vinyl/caulked/stapled sections. The reason the melamine/"wood"/MDF wall looks scuzzy is that fiberglass insulation was spray-glued to it.

One note is that the wall dividing the stove and refrigerator (as well as the opposing wall dividing the sink and shower) are 1/2" plywood, as opposed to the other walls which are MDF/Melamine. These two walls are somewhat "structural" in that they help hold the sidewalls in shape (otherwise they are a bit floppy, as fiberglass is). They are not tabbed in or in any way as structural as say, a bulkhead on a boat, but they do contribute. In my case the stove/refrigerator plywood wall was not actually screwed to the outer wall, but it was fastened to the ceiling, and then the stove was fastened to the wall, and then things were caulked and then that whole conglomeration worked together to stiffen things up. If you look at the Chinook wall drawings I matched up the wood strips in my walls (which were easy to see with everything out) and they do match up almost exactly to the drawings. From that you can tell which fasteners are really doing things and how to ensure any new construction is as good or better.
Another note is that while it didn't seem to negatively affect anything, the area where the forward side wall of the closet (between fridge and closet) and the outside of the rig meet... well, that "joinery" was a bit shakey. Again, nothing that actually caused anything negative, but definitely could be improved. They relied on those vinyl/wood caulked in sections to do some closet sealing there.
Now, on to mockups.
Basically, I have four options. The refrigerator that is my first choice is 4.7 cu. ft. with a separate compressor. The separate compressor is nice for a couple of reasons. For one thing, the bottom shelf of the refrigerator is a real, full-depth shelf instead of a wee fragile half-depth drawer (or on some other models the freezer gets smaller, depending on where they put a built-in compressor), and for another you can insulate the snot out of the refrigerator box as it needs zero ventilation. Then too, you can provide lots of air for the compressor (separately). That's the route I'm going regardless of fridge model.
So, four options:
1) The bigger refrigerator (of the two I'm considering) is 31" tall. If put on top of the generator box (old refrigerator position), that's like a bar height counter (around 43" tall). Then the stove stays in its usual place at a regular counter height (which will likely be around 34" as opposed to the Chinook stock 31-7/8" on the Concourse, which is pretty low - standard kitchen height is 36").
2) Put the bigger refrigerator in the "stove place" which would sit on top of the wheelwell. (Wheel well is about 6" tall, generator box is around 13" tall.) Then move the stove to where the refrigerator goes. This almost yields one long "normal" counter height, but not quite because it all ends up being around 38" tall.
3) Go with the smaller refrigerator (Hoosier I think it going with this one) and put it in the refrigerator spot. This ends up being similar to #2.
4) Go with the smaller refrigerator and do the switcheroo, as in #2. This ends up with a long/low counter as in #2, but can achieve a more normal counter height (34" or so).
I really don't want the smaller refrigerator (it's quite a bit smaller, around 2.6 cu. ft as opposed to the larger one at 4.7 cu. ft), and I also didn't really like the switcheroo of stove/fridge spots. Which way to have the fridge open was one reason, and the other was that I was looking forward to having a "staging counter" that was optionally part of the kitchen but not "really" part of the kitchen. I go out hiking or other places and like a spot (besides the floor or couch) to set things I want to take with me, or am bringing in. I can also use it as a kitchen set down space, but it doesn't "always have to be" kitchen. This fits with option #1 and the bigger fridge with the higher "bar height" counter. So I'm pretty sure I'm going with option #1, although I can see the other options being good too, just depending on personal taste/usage patterns.
Here is a mockup of the "bigger" fridge in the refrigerator position, where it would have a bar height countertop (option #1). The red line on the left is the stove counter top line, more or less:
Note the un-loomed wires up near the top of the compartment. These had some "marks" in the insulation that I think were caused by the back of the refrigerator. No actual rub-throughs to bare wire, but I'm glad that I can now protect them better.