Today we did it. We went into the "can't turn back territory," we cut into the trailer.
This morning, we took turns drilling out the rivets holding the inside shell in place in the back. Removing it involved unriveting all of the window trim and rivets to adjoining pieces. The next pieces of aluminum overlapped the back one, but we were able to remove the section by lifting it out. The only complication was that there were several rivets layered under the overlapping pieces. I had to pull those sheets out while Rick drilled out the rivets. The whole experience made me very aware of how much slower I was at the drilling that Rick, who frequently does similar work when he diassembles control racks at the plant.
Once we had it all down, Rick started cutting a hole in the subfloor. He started small, then we looked in with flashlights to see what was ahead of us. Then, after a quick call to Stuart Natof, he measured off a space between the two diagonal frame members and enlarged it with the jigsaw.
Another odd note--in the middle of our efforts, a violent thunderstorm hit. Somehow, a tiny bit of the rain leaked up into the bellypan. We're not sure how that happenened, but maybe we'll figure it out as we go. There's going to be more effort to get at this, but so far, so good.