The panels that don’t glow on the floor are simply cardboard painted black and placed in areas where I couldn’t cover the plexiglass.
To make the “Bacta tanks” with the corpses “glow”, I bought some “stick up” lights at Walmart and using a Door knob cutter and my drill, cut holes in the cardboard under the tanks. When I wanted them to glow, I simply slid the tanks aside (their bottoms are the same translucent plastic as the tank!) and turned on the lights, then positioned the tanks over them!