A couple more pictures.
The wood goes on the walls and ceiling easy enough. We used 1/4" birch plywood lain against and screwed to the aluminum skin.
When I do another I think I would try to use 1/8" to see how it might work. The wood is not only attractive, it seems to help slow heat transfer in and out of the trailer.
The end cap was a little challenging, lots of measuring, cutting, and trimming to make everything fit nice and tight.
The trim hides the joint lines, the exposed screws on the trim makes everything quick and easy.
This trailer was my first carpentry experience.