Back in the day (1980s,..and TV stuff was everywhere, at reasonable prices)...I had bought a couple early RCA Neon's like that...and one or two with broken letters. I could get the signs neon tubes replaced/rebuild and re-filled, but I was told the new colors could not duplicate the old colors.
If you could find some new-old-stock coated tubes, and of course someone that would work with them, you'd be in the New-old-neon business
