Here is a sample of our flooring. We are going to use torn up brown paper, stuck onto the floor with a mixture of glue and water and coated in polyurethane. It was really easy to lay down this test patch in the corner of the trailer. I got the idea from an article on Recyclart. We will probably add a bit of black Rit dye to the glue, to turn the paper black. Using paper ought to break up all the wood we will have inside, visually. We are planning on using beetle-kill pine tongue and groove siding, both inside and out. With a black floor, it ought to look nice and goth. I am really looking forward to doing the whole thing.