I recently had to replace the lower door that covers the tank area on the passenger side of my coach. I decided to use the external skin from that door to make the shelf for my battery compartment. Using the plywood pattern, I have cut, fitted, and partially screwed in place the new shelf. In case you notice, the skin has a glue line from where the factory glued Styrofoam to the door (to fill space). I am not concerned about that. I don't plan to carry anything in this area. I am just trying to limit the road dirt that gets in this space when I am a trip.
Under the heading of "no good deed goes unpunished," my generator would not start today for its monthly maintenance run. That just makes me mad.