Chip,
Remember that a night dio deserves to be in a shadowbox for the best results .... the trick with shadowboxes is the way light is provided and with balanced light the background will disappear completely.... I would love this to work for you, but I fear it's very difficult and maybe even impossible. If, on the other hand, you do manage to make a convincing dio with this background, you'll deserve my greatest respect.
Keep us posted, I would like you to prove my thoughts wrong !!