After reading Lenore’s blog post about the nixie-based font, I went looking for something similar with open font license. No joy, unfortunately.
I did, however, find an OFL font that perhaps fills a different vacancy in the growing Hershey fonts constellation. It looks rather like Courier, though it is said to be influenced by neon tube design (I must confess I don’t see any neon influence, however.) It’s at https://fonts.google.com/specimen/Nixie+One
I’ve added this derivative as EMS Nixish and EMS Nixish Italic. And documented both in the now-canonical style. And here it is in dropbox as version 2.0.2: https://www.dropbox.com/s/ve4qdcvda2utzbs/hersheydata%20v2_0_2.zip?dl=0