WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
That's a nice collection and I recognize some of them. I have a small collection of big bottles myself. Perhaps the rarest is an Eimac 4-750A tetrode. A prototype that was never produced. The only other one I know of is owned by a friend in upstate New York. My biggest, a 24" tall triode type E4000/10,000 (sorry, no camera at the moment)
He must be the European equivalent of Ludwell Sibley (also of the TCA), who is probably THE authority on vacuum tube history here in the US. Had a chance to speak with him at the CC-AWA Spring Meet in Charlotte a few years back. He's a real gentleman, and has probably forgotten more hollow-state knowledge than I'll ever acquire!