I think I'll be unwinding right there after work tonight.
Here is a neat very old tube to look at
It is a Tungar Bulb or tungsten argon rectifier
It can handle 6 amps output at low voltage. You can't see it in the picture
but there is a blue ball of plasma around the filament. It can be used in
filament power supplies for direct heated triodes
I think I have a few tubes in my hoard with bases like that. I had wondered what they would be used for. I'll have to look for them and get the numbers.