Hello everyone -
So, some important progress has been made. I've installed 4 gas struts, 2 each on the front and back walls, using some heavy duty Simpson tie plates to create custom brackets that keep the struts out of the way of the roof skirt when closed (emulating the strut design of some of the Esterel campers of this type).
First I tried it with just one strut on each wall, but it was too unbalanced. Two on each wall work much better. I have two 150 lb. struts on the front, which is higher and tougher to wrangle, and two 100 lb. struts on the back wall, which is easier to handle. I have some 120 lb. struts on hand that I'm going to try on the back wall and if I like that better I'll go with them.
Another problem I encountered (prior to installing the struts) was that when the front and back walls were up and supporting the roof, but the side walls were not yet up, the whole structure was dangerously unstable and wobbly. So I installed some metal brackets ("closed bar holders") along with the stake pocket/brackets that came with the HF trailer on the front and back of the base. 2x3 supports go in these brackets to prevent the front and back walls from leaning out over the trailer on their respective sides until the side walls come up. Meanwhile the newly installed gas struts keep the front and back walls pushed up against the 2x3 supports, so the walls can't tilt in towards the folding position.
Long and short is I can now put it up and down by myself without too much trouble - the old timers who asked how I was planning to put the thing up and down were right! Super sketchy and rough doing it with manpower alone. If you're building something along these lines and you're of small stature, I'd also recommend making the overall height slightly lower than mine is. With the struts I can handle the front wall fine, but I actually stand on the tongue box or a step stool to make it easier. And if you're building something along these lines at all, then plan on using gas struts or something similar for lift assist. The veterans were right about that!
Next up is to install the chimney flashing and boot and the fantastic fan. Then the doors, already made, need to be hung and have hardware/knobs installed. At that point it will be ready to be moved out of the garage and to be camped in, though it will just be an empty box at that point - a true hard-sided tent.
Here are a few shots and a gif of how the back wall opens from the closed position: