Worked on adding the second layer of 1" foam to the front curve. Performed the kerfing using the hot knife and all went well. Slathered the PL P3 glue all over the existing 1" foam already glued in place, and proceeded to glue on this second panel.
Then, just as I was positioning it in place for glue-up on the camper, a breeze wafts through the garage, pushes the precariously placed panel backwards, and CRACK, the foam board split in half at one of the kerfs. I apologize to any children within a half-mile radius because I let loose many choice expletives.
Working fast, I glued on the lower portion of the broken panel, then placed the upper errant piece in place. Luckily, and with the help of 3" coarse-threaded screws and very large washers, I was able to clamp the upper section in place. I had no idea foam could hold screws so well, but I canted them at an angle as I frantically screwed them in, and thankfully they held the panel in place. Not leaving that to chance, I cobbled together this Rube Goldberg-like jig to brace everything in place as it dried:

With this catastrophe somewhat averted, I attached the stabilizers in the rear:

On reflection, I suppose I should have placed them closer to the sides for more stability, but I tested them by laying down inside and shifting around, and nothing tilted. So hopefully, barring gale-force winds, it will stay upright.
The air conditioner is test-fitted in place in the rear of the cabin. It will vent out and down through a hole in the galley floor. Looking good!

After everything dried and removed braces, the front curved section looks pretty good. I put an extra bead of PL in the gap between upper and lower sections, sanded it down, and it really looks safe and solid. Catastrophe averted!
