Thanks!
IIRC, I carried a tiny screwdriver around that fit in the clutch head recess. A couple of pokes and twists with that allowed the clutch head bit to reach good insertion. I wouldn't file the bit, after a few hundred screws it will wear on it's own. I bought a few bits at my local big box store, Menards.
For roof support and in order to keep all as square and plumb as possible, I made a jacking "tee" with 2x4's. A small hydraulic jack offered lift under the "tee". I have a full-height shower stall that also offered support (was constantly in the way, too.).
I'd keep the postcard and put it in a small frame, it would be a good conversation piece hung on the wall.
I've got no idea about your skills, work habits, or plans so you can accept or discard this advice, as needed: Removing all of the fixtures, paneling, and floor coverings will allow you to have a blank canvas, uncover any rot and flaws, and allow for upgrades to electrical, plumbing, and insulation.
Draw out plans for the different phases or aspects of the restoration. They don't need to be engineer quality schematics but it will save you time through the project as different stages and features are installed. It isn't any fun tearing out part of your work because things don't coordinate in the same space or one part needs to come before the other. FWIW, I only missed locating one electrical box (fridge) and covered one forgotten switch location.:B
Depending on your needs and budget, a couple of things that worked well for me were replacing windows with Low-E residential sliders and insulating with foam board, both in the wall cavity and across the studs for a thermal break. When I'm in the trailer, there is virtually no outside noise and it is very easy to heat and cool.
Good luck with your Holiday, if you need any help, send me a PM.