[cctalk] Concorde cabin display technology?

Not quite computer tech but I figure this is the best place to ask: Does anyone recognize the display tech that was used on the Concorde's in-cabin display? Examples: https://samchui.com/wp-content/uploads/2016/02/CON15.jpg https://samchui.com/wp-content/uploads/2016/02/CON16.jpg The display had fully-formed digits and letters, and showed either Mach and Feet, or Temp and MPH. Some pictures show the display in green and others show it in orange - which of course were popular monochrome CRT colors, yet the display looks too "flat" to be a couple CRT's. Those colors were also popular for Electroluminiscent displays which matches the evident "flatness" but I'm not sure I've seen any EL's with fully formed digits like this with no visible segmentation? I want to guess it was individual digits back-projected - which was a popular control-theater display tech at the end of the 20th century - but I can't rule out, say, really well-done edge-lit character plates. In any event there doesn't seem to be any visible jitter up and down between digits that I might expect with either of those technologies. The "FEET" display in the above-referenced JPG's shows some artifacts at the left and right edges which might be a clue? Some pics of the BA Concorde interior had a simple 15-segment and 7-segment green LED display. Don't need help with that one 🙂. Tim N3QE