On another note.... I did not go off the deep end. I just went to a local tube dude. He had walls and walls of beautifully displayed tubes - see last pic for just the lower half of one of 8 display cases. If you squint closely enough the "red bottom RCA" is on the left on the 2nd shelf down.
I didn't know too much about what I was looking at (or for). He had the aforementioned famous RCA "Red Bottom" and Ken Rad VT-231's, but I have no idea how to check them, and while the price was in line with expectations, I'm not quite ready to take that kind of leap. So, I decided to stick with trying 4 "families". I got a Sylvania, a Westinghouse (I think it has a D getter, but I have no idea if it's "the" D-Getter), a Ken Rad, and yes.... a GE.
The writing on most of them is so faded out, I have no idea how to check the provenance. I'll just plug 'em in and go from there. Starting with the unknown Ken Rad.
[Edited to try and fix pictures, but they're not displaying on my editing window - will try to repost or edit]
[2nd Edit - Dang... those are huge... sorry I'll try to resize]
[3rd Edit - I am clearly not an expert... but I think I got it... inserted thumbnails]