In particular, before you glue anything to glass - or otherwise make any modifications to the bases of these collector's items, you should take a look around to see if you can find any tube sockets to match them.
For myself, I would feel better about modifying the socket ( if that could provide useful effect ) as opposed to risking harm to the tubes.
Although... some of those old ceramic-based sockets could look almost ( though not quite ) as impressive as the tubes, themselves:
According to the Mock Electronics site your big tube is a JAN 450-TH. Doing some Binging I found it equivalent to a VT-108, or replaceable by a HK854H. It's a triode transmitter, air cooled. The specs on the HK458H say its a 450W plate dissipation at 125Mhz. Another site uses a 450-TH in a Class A audio amp rated at 160W.
I've always fantasized about having a vehicle with two or four 10KW or better amps with speakers good to 25 to 30 KHz mounted on arms that I could deploy on each side of a car that's blasting its music so loud I can hear it through their closed windows and mine. Pipe through it a little high-pitched opera or some English Lute Music (sorry, Max, I like the lute but not the high-pitched soprano), let it run while waiting for the stoplight to change, and presto: Revenge!
I always envision the other car crumbling into dust as if it were in a cartoon.
And yes, I would take a bow to the standing ovation. ;- )
This link has some history on the history of the 450-TH tube.
Uh-oh: have you placed your geiger counter near the tube? This link claims that the filament may have some thorium in the tungsten, and it may be radioactive. Is that where you get your glowing personality?
@Cwrobe: Try some frosted scotch tape for the experiment. No damage to any of the tubes and you can approximate what it will look like on the actual tube. I think. :)
I will certainly try that as well -- good idea -- but I'm not sure that will give the same effect as actually etching into the glass (the tape will act as a diffuser, but the etching will scatter the light in a different way).
But don't worry -- I will practice on a big back of small, cheap, broken tubes that I have here in my office. I'm not doing anything to those big tubes until I'm 100% confident that I knwo what the result will be...
Another idea is to etch a band around the bottom of the tube and then put a ring of NeoPixels around -- I'm thinking the etch will get the light into the glass more effectively -- but I'm experimenting with some small, cheap old tubes first to see...
Try some frosted scotch tape for the experiment. No damage to any of the tubes and you can approximate what it will look like on the actual tube. I think. :)