Have you measured the output of the AC conversion transformer, or are you assuming that it's really putting out 110 V and isn't malfunctioning?
Where exactly are you located? I'm confused as to why there are either no techs available, and/or the ones that are there have no interest in accepting your business and money.
Are you the only person with a guitar amplifier where you live?
Regardless, how do you expect that a bunch of people on an internet forum can diagnose your amp issues on line and give you a "magic" cure for it?
As I mentioned earlier, you need to find a qualified tech locally to fix you up; these old amps aren't very hard to fix for a qualified tech, even if they have never seen a Sunn before.