Before excavating further decided to take a pic of the now obvious ingress
of damp down the HT wire. Lovely green copper carbonate staining.
http://home.graffiti.net/diverse:gra.../home.graffiti.
net/diverse:graffiti.net/K2F_c.jpg
and the other cap interior where the contact breaker connection is from the
centre fixing , insulated under and around , by what looks like a black RF
coil former
http://home.graffiti.net/diverse:graffiti.net/K2F_f.jpg

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/