I've been restoring some old equipment and run into a brick wall trying to replace the damaged front panel display window. One meter uses Nixie displays and has an amber colored window, the other uses a 7 segment led display and would need a red tint. The thickness should be ~ 0.9mm/.035" . I tried a spray tint on some vinyl page dividers obtained at a office supply store but not only did the paint adhere poorly; the clarity was miserable . Tried milling down 1/8" tinted acrylic with a Dremel. Fail. And lastly investigated several suppliers of gel filters but can't seem to get an answer on the thickness. I'm hoping there's a brainiac that knows of a source.