OOPS! How to Fix an Old Tube Cap?

[Winky Dink]

I'm in the chassis dust-removal stage of restoring a 1931 Airline console. I pulled the connector off a balloon-type 24 tube and I thought "Gee, look how they made these tubes! There's no metal cap--just a wire sticking out of....oops."

So, how do I replace the cap? I have 1/8 inch of wire from the tube that I can solder an longer wire. I'm guessing that if I desolder the separated cap and remove the goop, that there'll be a hole for the wire, and that after I can thread the elongated through the cap, fill the cap with new goop, reseat the cap on the tube, then solder the wire to the cap. (If I'm not making sense, then see the attached photo)

The question is, what kind of goop can I fill the cap with that will be adequately heat-resistant and adhere to the glass?

I've posted some pics on PicasaWeb:

http://picasaweb.google.com/coldrb/A...eat=directlink