Some of my fondest early foreign traveling memories were going to places in Europe and traveling from city to city where the train and airport arrivals/departures boards used these amazing electro-mechanical split-flap display boards. The last place I saw one still in use was at Frankfurt airport in Germany a year or so before covid (and I believe it’s still there):
Even better, all the parts, software, 3D print resources, and information you need to make your own can be found on his github page: https://github.com/scottbez1/splitflap
But be forewarned, his estimates run around $200 to make only 4 of these wonderful digits.
Also, there are now companies around that will make these displays for you:
But be ready to pay $2800 for even a basic model. This guy does a decent job summarizing the current offerings.