I wasn't sure if I was going to hand-wire this or have a PCB made for it, and after mapping things out I decided that a PCB was certainly necessary. There's over 250 solder points which would have been nearly impossible to do cleanly by hand.

The front side of the PCB has only the rotary DIP switches and some LEDs to light each dial up to indicate when it can be used. Beyond those components, it is flat and should be easy to integrate into a housing. The PCB is sized to fit within the 180mm × 200mm faceplate that can be made on a standard 3D printer, however the upper dials can be snapped off and relocated via extension wires to allow for any size/shape of dial configurations. There is also an unpopulated header for a 4th dial that can be optionally added.All

All external connections are spaced to accommodate JST XH connectors which are common on arcade buttons and other devices like the mini receipt printer, or wires can be directly soldered.