On Wed, 09 Mar 2016 23:57:37 +0100, Dimitrij Klingbeil wrote:

Looks like you've got it going back to normal operation, finally!

Yes! I can confirm it is now back up and running and early checks don't
seem to show any other faults. I've got four nice bright sharp traces and
all the buttons and knobs seem to do what they should (although I haven't
exhaustively tested *every* single function at this time, of course).
The only error I made was switching it back on from 'cold' - it clearly
hasn't been on for a long time and I really should have brought it back
to life on a variac but I forgot. There were some initial crackling
noises and whatnot but they gradually subsided; some noisy knobs
obviously as only to be expected, requiring lubing up but nothing else
noteworthy.

Many thanks again to all who assisted. The kids at the local school
electronics club will soon have a new toy to add to their test gear.