Nice set up you have there. I agree, solid axles for me as well. Are those additional struts on the side of the 4WC? Did you do the front axle work? One of the primary reasons I went with a Ford 1 ton is because it has a SFA and I’d settle for nothing less. I’ve a Grandby flatbed, and once in a while after a lot of technical & washboard miles, the cabinet screws across the bottom weedle themselves out. I’m trying to find loctite for wood screws. LOL Anyway, nice build, that truck looks good.
Interesting, I've never had anything back out in my Hawk, and it's seen tens of thousands of miles of washboard and technical trails. I've had a bunch of RVs, and in most of them after a long road trip there's always some "sawdust" around from stuff falling apart (not so much with my Newmars), but I've never had anything like that with the FWC.
And yes, those are additional struts. I have a lot of solar, and an AC/heat pump on the roof:

The additional struts are to deal with that weight. I think we went a bit too heavy on the struts overall; it's a bit tough to get them moving at first (up or down), but it works, and I'm fine with it. Hindsight 20/20, I'd probably have gone with a bit less solar, a bit less battery, and added more water capacity where the "extra" batteries are. I can run the AC for over 24 hours off the battery bank... which is just unnecessary. The way I use this rig, I move daily on 99% of my trips. The only times it sits in one place for a few days is generally at my family cabin (it's a small cabin; you don't sleep inside; we have sleeping porches, and this is the truck I take there anyway so I sleep in it). At the cabin, I'm not in the camper much at all other than sleeping, and I generally don't need the AC or heat, so I'm not really using the batteries. With the 2nd alternator and big DC-DC charger moving daily on the trail, it charges everything back up, so I could have gone a lot smaller with solar/battery.
That's an obvious $100k. Or close to it.
I try not to do the math, but I'm sure it's well north of 100k at this point. Again, that's over ~16 years, though. I paid ~$52k for the truck (against a > $59k sticker) back in '10 (it's a 2011 I bought in Oct of '10). The SAS was initially done at WFO, and also included rear axle work (regearing to 4.56 to match what we did in the front, re-drilling the axle flanges to 8x170mm, all bearings/seals, ARB air locker, etc.), having a custom skid for the big 60 gallon fuel tank built, the new wheels (since I went to 8x170mm bolt pattern so I could do the free-spin setup up front) and the 37"s it got back then (I'm on 40"s now) and a bunch of other misc stuff. I don't really remember, but that bill alone was $30-40k.
The FWC was mid-30s. I just dumped $ into a huge lithium battery bank, inverters, a ton of solar, ditching propane and going all-electric, AC/heat pump, a big DC-DC charger, etc. etc. on top of that. The rear suspension is a modified Kelderman air suspension 4-link. Then you have all the stuff like bumper/winch, custom sliders, RIG'd rear tire swing, 60 gallon fuel tank, nice stereo/interior work (that stuff was done before it became an Expedition rig, all the headliner A/B/C pillars and various trim pieces are black Alcantara, it has a ton of sound isolation material in it, etc.), rear seat delete, Mishimoto radiator/intercooler, aftermarket charge pipes, aftermarket coolant lines, aftermarket turbo, tuning, full exhaust, lift pump/filtration, lights, radio, rear seat delete and flat rear door panels, complete rework of the steering with hydro assist and custom trackbar to eliminate bump steer, and a million other things I'm forgetting. It's also been way over-maintained, with all Amsoil fluids.
If I had to guess, I'd think I'm closer to $200k into it than $100k. I don't say that to brag, or because I like hearing that number; I'm just trying to be honest. I always say, "you'll have to bury me in this truck," and it's worth it to me, but for someone considering something like this, it's useful to have honest numbers.
And it's not "done" either. Next, I'd like to do a custom AL bed on this truck. I wouldn't do a flatbed, since that would mean getting a new camper, and it'd place the camper higher (the last thing this setup needs is to be taller overall). I also don't feel like I need more space in the camper. However, getting useful storage on the outside of the bed would be really nice. After that, I'd like to make the front suspension air as well, but being a SAS'ed Chevy, it's not as simple as just getting a kit from Kelderman. With the custom bed, one goal would be much bigger wheel wells, so combined with some front-end work, I could keep the 40s and get the whole rig sitting a bit lower.
If I were building something like this from scratch, I'd start with a Ford (for a solid front axle), and I'd probably do the Kelderman front *and* rear. So you're starting with a ~$80k truck and $10k of suspension right off the bat. Add steering upgrades, including hydro assist, wheels/tires, skids/slider, bumper/winch, etc., and you have another $20k of stuff really quickly. FWCs are now more like $50k+ and wouldn't even have the battery bank, inverters, etc. I have. Again, if I'm being honest, I think it'd be close to $200k by the time you duplicate this setup's capability. You'd have a newer, nicer truck with fancy stuff like adaptive cruise, and it'd still be way cheaper than stuff like Rossonsters and Earthroamers, which have their own big advantages, but also can't get where I get, or a "new version" of this setup would.