Backlit panel

I remember Linda Rice's Lockheed had a really cool backlit panel overlay.
The panel itself was heavy aluminum sheet, but then they added a plastic
overlay that had an opaque cover. Legends and labeling was done by
engraving the opaque layer.

On the back side of the there were little cavities carved for grain of rice
(well duh!) light bulbs.

The effect was quite stunning.

So does anybody know where to find this kind of plastic for the overlay?


Thanks,

Richard