What area in joburg are you? I do repairs on valve amps as well as build custom ones, I'm based in Ruimsig, Roodepoort, but I'll hook up with you where ever you are. I've repaired quite a few classic 30's and am quite familiar with the all their quirks too.
My contact details: Cell 082 560 7257, email
jp3zone@gmail.com
best regards,
J.P Le Roux