Possibly worth looking at https://www.myfonts.com/fonts/kinobrand/nixin?tab=glyphs which appears to have been designed as a 'nixie alike' font. Though it puts a foot on the '1' in ultralight(but not on other font weights) and has a closed '4'. And of course it is not free.
Of course it depends where your nixie tubes were made... if they are genuine Nixie or ...
I don't know the exact font but I have a few ideas for your project (would really like to know what font it is though):
Period accurate geometric sans serifs for a jumping off point:
Univers - 1957 Futura - 1927
Also a condensed geometric font like Gotham Condensed (based on Futura but made in the 2000s) may give you the effect you want.
For the nixie ...