Many thanks all – some good leads to work on!
Based in Esher Chris.
These are pics of the clock as requested Neil.


I made a similar one many years ago with individual ICs and a transformer to supply the HV. This one is a mix of old and new tech. The main PCB is from a company called pv electronics and contains all the drivers etc. including the 180v supply for the Nixie anodes. The wiring to the Nixies is very much 'old school'!
Still haven't decided to chrome the front panel or just polish the brass. The case will be a light maple with comb jointed corners.
Apologies for the lack of Model Engineering content in the post but the holes in the brass were cut with the 'Rotabroaches' from Cromwell tools. Very good price!