The tubes used are the IN-14 which are driven by the high voltage display driver HV5812. Time is kept by a PIC18F1320 using the DS32KHZ as an oscillator. The PIC also controls the step-up converter responsible for converting 12 V input to the approximately 150 V required to fire the nixie tubes.
Code has been confirmed to compile with xc8 v1.33 using MPLAB X v1.95.
PCB design files in kicad format can be found in the kicad folder. They have been produced using kicad 2014-12-26 BZR 5338 built for OSX 10.9.5.