Making your own flip digit display involves some drudgery in the production of all those flip cards, but how would it seem if the complexity was reduced? Go from base 10 to base 2 for example ...

Four of these modules connect together to form a row of 32×2 digits, and eight rows of digits come together to make a 512-digit display. With seven LEDs for each digit, that works out to 3,584 ...