That sounds like a lot of work. The one I found is regular door thickness and is already drilled for a standard lock set. I'll have to beef up the door frame in the side of the trailer, or shim out the door mounting to make the lockset bolt center on my 1 1/8" thick side wall, but I know I can make it work. I could use a thicker frame around the door edge. Cutting an opening in the door to fit in a window won't be a problem either. I may have to remove some foam and fit in some frameing just inside the cut edges to securely hold the window flange screws. I'm trying to keep costs down, but also will trade off some additional cost for less work.
I recieved an email today from Kevin in TX. He visited a shop that builds teardrop campers,
www.happitrails.com using a lightweight laminate of .05 fiberglass sheet, 2" foam, and 1/8" plywood. There's no framing except where they need to add some wood for screw/nail points inside the panel. I emailed the owner and he wouldn't tell me how they achieved a curved panel. He said that is proprietary...spoil sport.
So, I'm staying with my framed walls, but will consider a FG sheet skin before I do start building. But, I'll probably stay with the 1/4" plywood. Has anyone built with 1/8" plywood inside and outside? If I did, I'd make the framing 1" to 1 1/2" thick, not 3/4". Then, it probably wouldn't be any lighter, just easier to curve and have more insulation. That would be a good tradeoff.