Behold, Philip de Cadenet signalled from keyed 4-1000A filament:

Hi Gregg,

does anyone happen to know of a UK source for any of the following
parts:

Unelco/sprague type metal clad capacitors

25 ohm semi-rigid coaxial cable

Philips 'Blue Spot' or similar high voltage RF trimming cap's, min
300v working (65pf).

There are some very inexpensive Russian mail-order houses too.

I'm aware of one or two Russian valve vendors but have not noticed any
component dealers.

If you can pass a URL or three it would be appreciated.

We speak Russian!

KW Tubes was one of them, http://kwtubes.com/

Lithuanian, not Russian - silly me ;-)

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca