Repaired one today- dry joint. Main glass sphere contains a small glass sphere that is probably aquadagged , on evacuated side or internal surface connected to the tube to the outside world or both surfaces ? The wire from the LOPT type transformer would seem to touch this small central sphere. Surrounding this LOPT output wire the length of the connecting tube is a length of helical wire reinforced plastic, like vacuum cleaner hose. This hose on the outer end is retained by a rubber cup. Is this 'hose' a cosmetic piece or functional ?. I Don't know if the innermost end of the helical wire is connected to the central sphere or anything.
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on