Unfortunately it's only lasted about 3 months
Back with me for investigation- so far I've found that the mains TX has died. It was taking out 500mA fuses on its input and when tried on the bench out of the unit straight on the Safebloc it emitted the magic smoke.
Unfortunately it's an odd size and has a 10V off load secondary so it may be difficult to find a drop in replacement.
The clock itself looks promising, fed with 5V dc and mains for the nixie supply, it lights up at 014000 but without a 10V ac supply to trigger the counters it doesn't do anything else. I've got some old 220V : 6.3V mini transformers which give about 9V off load- I'll try adding that to the mix tomorrow to see if the clock really is OK. They won't do as a fix, though, I know from looking at their waveforms that they're running into saturation at 240V input (they came from a French vide-grenier many years ago).