I found an old piece of hardware for sale at a local second hand shop. It's a "Schneider CF315":

There is not much that can be found online about this device. I did not have a particular use for it, but saw that there were 6 nixie tubes in there. The enclosure looks a bit battered. Some knobs where missing the cover. Otherwise, it seems to be working. I thought of turning this into a nixie clock and bought it.