In the past few years, we have covered a bunch of gorgeous Nixie tube clocks here. The Time Compressor V3 is also worth a look. It is a Steampunk IN14 Nixie clock made with brass, copper, wood, and bronze. It can display the time in 24/12hr format. You can power it with a 5V adapter.
Valery from TheTimeOnTheWall is behind this amazing clock. You can find it on Etsy.