Here is my big "conclusion" post. Usual typos apply. I hope it helps...!
_____________________________________
have to apologize I've been a little MIA on the trailer front as I have a lot of pictures especially of the trip. It was 1000 miles, tons of on and off road including some fairly "hardcore" or significant challenge with my truck on 33's with open diffs.
The trip was pretty much, hands down, the most amazing Southern Utah trip I've ever had. The trailer was sort of a character in it all but it certainly was a nice compliment, it was pretty neat hauling and testing this crazy little unit that followed me around. Not sure if you was Beemer Chef's blog,
The Oasis Of My Soul Ara and Spirit: Life Under the Stars - I spent a few days with him and he was updating it as we were there, he has some absolutely wonderful pics of it all. I plan to write it up as it sounds cheesy but this southern Utah trip really had some "soul" to it. It really was special...
Anyway, Yooper to answer your question and to everyone else...
1) The number one regret... The tailgate. Sorry this is so wordy: with the hydraulic lifters, the lid is so easy to pop open. I literally never used (or even thought to use) the tailgate once. It is also a bummer because it lets dust and air and rain in even with the weather stripping. If using hydraulic lifters, my strong vote is do not cut a tailgate. I am really actually quite bummed about this and am looking at solutions for either a new tailgate that is stout and easy to us, or possibly even just welding it shut (which it's probably too late for that. My closure system: I liked it a lot when building but.... It took some "alignment" once painted/final assembly to get it to close right. It is a PITA. It is strong and hard to break into which is nice. But currently reusing the current tailgate, it is a PITA.
This might be some of my concern as well, I think I'll start with a new one from scratch next time, possibly also using the same paddle latch system of some sort. But again, not overwhelmingly pleased. I'm sure it will be nice for something heavy, but I am a strong guy and nothing really crossed my mind for a legitimate need for it...
2) The trailing arms and the frame strength. I'll start posting pics when I start getting to it (taking a little break and/or working on other projects). But I will be cutting out the cross member where the A arms mounted. It is tweaked noticeably after heavy offroading and both tires came home canted in. A bummer, but such is life and can be expected... I plan to purchase the steel shortly to put in a new cross member that is much stronger. Anyway, I think I can bang all this out in a day or two so not the end of the world. I also noticed some "breaking in" with the trailing arms as well. Very minimal but I wish I had somehow made the arms adjustable. When I redo the cross member I'm going to completely re-align the a-arms -- this time by laser -- to make sure they are 100% correct...
3) The rest are little nitpicky things.
I had some slight issues with my old Thule bars (mostly the clamps) and mostly when really rallying hard on severely rutted trails and roads. My little truck is IFS with soft torsion bars (lift brought on by ball joint spacers) and with the Old Man Emu soft rear suspension its not much of a good "off roader" or a "wheeler" (in fact its a little limited - mostly by its lack of droop and a few other big reasons) --- but, it's a hell of a little baja truck. I have taken lines and at speeds I never have been able to do with a Land Cruiser before. Very nice. But as a result I really rattled the crap out of the trailer so it exposed some weaknesses. Such as reason #2 above and (obviously) the need for very strong mounting systems.
The drawer worked really well and it was the first time I was really psyched with how the kitchen turned out. I tried to do this trip relatively low budg, or "dirtbag" to an extent as me and some friends are calling it. So I spent a lot on really nice groceries (top of the line bacon, lots of avocados and black beans, etc)... So I wanted to commit to my food rather than eating out as its so tempting to do, particularly in Moab...
I have a 1/2 dozen other little nitpicky things, I'll post up about them at some point. Nothing major but for you guys hopefully there is some good info I can share...
_______________________
ALL IN ALL...
The trailler really performed flawlessly. It follows you "everywhere" and is also a good fairly advanced off road design. With the A arm design I did and my approach on ground clearance I really think it could really off road very well. Trailers are little complicated off road. They go great forward but even with the tongue enhancement, particularly in reverse and in tight areas, they are definitely a liability. I had some romantic notions and really off roading heavily and possibly doing a "hardcore off road" trailer run some day, for example maybe Pritchett Canyon (this trail is so damn hard now even without one -- so it would be some adventure!). I've seen Kurt really off road the absolutely bee-jeesus out of it which was one of the reasons I built is and always was excited to. I still sort of have the wacky idea to possibly do this. BUT, I had had false prescience / romance of the trailer (which I still have) but I realized I slightly need to reign that in. This is one reason the retractable tongue idea is a good one though... This can possibly alleviate this. I was really really happy with the length and wheelbase and tongue length of it all though.
Also -- oddly -- I was quite happy with my pintle setup. I've had them before particularly with my old M116A2 flatbed 3/4 ton trailer, and really heard them bang and clank around significantly before. But... For some reason with this one, no issues at all. I only heard maybe a 1/2 dozen or dozen at absolute noticeable clanks and they didn't bother me at all. These were sort comforting, actually, as I knew they were still there. Mostly when I would have to brake to a sudden stop.
The best thing about it... It literally "follows" you everywhere and it also, totally by luck, tracks your vehicle to the t (or at least my truck). This was really really neat. The best absolute solution to driving it I found was
"pretend its not there." Even when I was fishtailing on the Comb Ridge road, where they found Everett Ruess, driving a little faster than I should but largely to test the trailer on that type of terrain, there was literally only one time the entire route that I conscientiously needed to make a correction because of the trailer and it was at 35-45 mph on tight but smooth dirt roads...
My little truck did a pretty good job of towing it. It clearly affected my mileage. Once loaded it affected it on the grades. I also fought some severe wind and/or even wind storms so I found that as well.
My truck is also very light and the engine sort of is just barely balanced for good performance out of that little V6. A Tacoma or most other applications are much better ones. But I also feel I learned a lot with the little truck. 1 is loading. I put in way too much (20 gallons) fuel and 10 gallons water and really heavily loaded it and somewhat left the truck stock or empty. Even with the balancing it noticably brought the rear of the truck down an inch or two. It was actually very nice driving and really balanced out the truck. I could lift/move the truck very easily loaded or empty, RTT open or closed, all of which was really nice. In fact the weight loading of the fuel/water does really help with tongue weight and loading. In fact I'm really psyched as I nailed that quite well... But it is noticably tongue weight. But my Old Man Emus are lights as well, so these are all factors to consider...
The only other thoughts I had (which I don't think I'll do) is it crossed my mind to possibly sell it and build a new one, the 15-20% smaller as I was suggesting, using aluminum for the shell and really focusing heavily on a light weight model that can be pulled by a variety of trucks.
If I were to do it again -- I would just start from scratch. It wouldn't have the character or even resale of a M416, but such is life. Nothing wrong with the M416 approach and it is a good application. The size, really is, about perfect. But it takes work to commit to this old platform/trailer. It is a restoration/modernization though, so it is different...
If I did it again, I was also considering seeing if Adventure Trailer would let me use their a-arm system to avoid the time required. I know they have concerns about trailers using them from people just calling any-old trailer an "adventure trailer." I'm also interested is seeing if they might have any interest in a small or a mini chaser similar to what I would construct. Sort of the VW bug or "working man's AT" particularly after the sales and excellent reputation they've gained but the price is out of reach or a luxury for some may people and I think it could hopefully be affordable with an approach on stripped down models.
One thing that crossed my mind is the M416 trailer is a very good size. But for me and even with kids/wife/family (right now its just me & my wife) I'll never be at a spot where I truly need a larger trailer as, pretty much, I don't own a Jeep/FJ40 as I own my FJ55 (and I'm building it sort of with the perspective of "for life" - similar to this trailer but a much larger [and expensive scale]. So this is my very roundabout way of saying I still stand strongly behind the 10-15% smaller trailer, "about 7 jerry cans wide" setup instead of 8, and really accenting the off road aspects and the towability by smaller trucks such as tacomas and FJ Cruisers etc in real off road settings. And then finally building it sort of as light and as basic as possible. I would definitely purchase pre-bent aluminum or mild steel for both the tub as well as to build a frameless lid. I would also use a thin 2x2 steel (the same stuff as what I used for the trailing arms -- or maybe 2x1) to keep it as low (and as light) as possible. This is also my roundabout way of saying ATs are noticebly larger and heavier than even my little M416. So I thought I about this quite a bit...
But finally, it did sort of exactly what I was hoping. It really was just a hell of a "basecamp" that I could put in place and leave behind for day adventures. Particularly with a larger or more powerful vehicle (such as my FJ55) it would really be a pleasure to haul around. With the mini truck, totally doable, but it is a compromise...
_________________________
So, I hope all this info and commentary helps! Also thank you all for all the wonderful PMs and questions. I really wish you all had just posted them up here (really no reason not to) but thank you all for your support...
Photos to come hopefully shortly... And basically some small repairs and changes as there is no reason to not continue to document them....
Cheers,
Andre
So I ended up selling the trailer. 
