A few years ago I bought and old bit of Solatron kit on eBay for around £15. It had 12 NIXIE tubes in it and was totally unuseable. So I strpped it and designed and built a clock for fun. Clock source is a CD4060 and CD4013 with a 32.768Khz crystal. Counters are 6 x CD4017's driving MPSA42 transistors for the NIXIE's. 180 volt supply is a switched mode type and the LED's are controlled with a PIC16F737 to give 16 selectable sequences. Time backup is 10 hours from a 4 farad capacitor. The base is beech and the case Perspex.