A visit to The National Museum of Computing where I admired a running Harwell-Dekatron/WITCH computer raised my interest towards the Dekatron "cold" tube (a counter once used to compute sums).
When it's working you can follow the computation watching the "glow" (electrical charge on a pin) moving from one position to the next.
Today this moving-glow device can be used as a simple gauge (one steady glow representing a value) or, by exploiting POV (Persistence Of Vision), as a multiple value quadrant, e.g., a clock!
Thus I bought (I'm lazy) a Dekatron shield for Arduino, an ESP8266 (with Arduino form factor sockets) and I mounted them inside a "vaporpunk" (not vintage enough to be steampunk) glass dome bolted on a painted wooden box containing a 220V AC power supply with a lever switch.
The sketch manages NTP syncing and the moving glow to represent clock hands.