looking at those "3"s.. reminded me of these old digit-showing tube lamps.. but their font is slightly different, esp. the 6/9 https://en.wikipedia.org/wiki/Ni

looking at those "3"s.. reminded me of these old digit-showing tube lamps.. but their font is slightly different, esp. the 6/9 https://en.wikipedia.org/wiki/Nixie_tube https://en.wikipedia.org/wiki/Nixie_tube