Tilby,
I am happy to hear my opinions on your project are helpful! It is always exciting to see projects as the develop, and offer up what little advice is possible to help it toward its full potential. If you are thinking of illustrating the walls, might you be able to make them a bit transparent? An opaque inner wall might hide a bit of your map, which I would think you would be trying to avoid. I look forward to seeing your work continue to develop!