Progress on my custom has involved experimenting on other caboose bodies. First, I painted the interior black to stop light bleeding through. Better but not enough. Second, once dry, I applied a heavy coat of white. That stopped the light bleed and dispersed the light in the car. Third, I applied aluminum foil to the floor. Another improvement. Number four lasted all day including paint drying time. I tried a number of methods to color and control the light . I liked the amber color from placing a cut down medicine bottle over the Lionel bulb. The plastic didn't like the heat. I may try painting a bulb. To even the light I tried plastic and paper inside the clear window plastic. Here are the "experiment" photos.