And a well know film about two years ago was the "actuator" for this idea - as the IN-18 tubes were rare and much more expensive than today - see below a screenshot.
Knows somebody this film from the 60's?
Great idea. Non-Linear Systems built digital voltmeters back in the 1960's that used a similar display technique. The layers of acrylic were engraved with solid characters, probably with a Dekel Pantograph. The edges were lit using #327 incandescent lamps, a whole bunch of them. There wasn't much to the electronics. It used a series of stepper relays that was configured as a Kelvin-Varley voltage divider, and a voltage comparator circuit that used a cadmium standard cell. So although the machine was slow and clunky, it was quite accurate.