Tail Lights and Roof Trim
there are no blueprints or instructions for this project. simply make it functional and make it look nice. That's the rule I work by :)
The rear roof section of aluminum overhangs the rear wall by about 2". I can either bend it over and rivet it to the rear wall or cut it flush with the rear wall and use the roof edge trim to seal the seam. My fear of using the trim is that it will hold water in a pool on the roof and my fear of bending the section over is that I will bang up the Finnish and have dimples in the aluminum. I do not have the correct tools or knowledge to bend this stuff correctly. I would imagine that the aluminum would need to be bent in a brake prior to painting to do this correctly.
Rear Red Marker Light. I am riveting them on and sealing them with the window and door sealant so the plastic has to be pulled back. I do not want to expose to much of the aluminum because im bound to get liquid nails on it and its a pain to clean that off.
The marker light is installed and I am happy with the rivet method. Here you can see how much the aluminum roof hangs over the back.

Left side Tail Light and Marker lights installed
Inside I installed the paneling right of the door and on the shower stall face. I framed the roof vent and trimmed the corner by the door.