Despite having been quite for the last ~2.5 years I finally got around to making some progress on this project. I've got the initial control circuitry rigged up, a mega328 board acting as the controller with a RTC to provide the timekeeping functionality and a rotary encoder to allow for user interface. I've got the code up on github. Currently the clock is up and running, it can display the current time in any integer base except -1, 0 and 1. The rotary encoder allows for changing the base as well as setting the current time. The time is displayed in HH:MM:SS form when room permits, seconds are dropped when room runs out and replaced with a blinking decimal point. If there isn't room for both hours and minutes to be adjacent then they are overlaid on top of each other (hours in red, minutes in green).

Things that still need to be done:

1. Throw together a schematic for the controller board.
2. Update code to allow for some more features (allow user to select display modes, utilize LEDs on the encoder).
3. Make a enclosure to hold everything together.
4. Take some pictures/video of the current setup.