Fahrney's Pens in Washington, D.C. used to sell a watch box that held six watches and had a clear plastic window on top. The box was made by a company called "Sir Rondo"; it was manufactured from pressed paper board, I think, or something like that -- it was supposed to simulate leather or lizard skin. The thing sold for $79.
Since it was sized for more convetional watches, the slots were a bit snug for G-Shocks, but I found that a watch box with a clear plastic top was a good way to expose my solar models to sunlight and still have my window sill look reasonably neat. The window I used never had direct sunlight for a very long time, I had no fear of the watches cooking in their own box.
Sir Rondo seems to have stopped making this model. Does anyone know of any other clear topped boxes that would be good for storing solar G's and allowing them to be exposed to light even when they are "put away"?