Power amplifier longevity… thoughts?

I'm new here and I don't want to do anything inappropriate but awhile back I posted that I have a new Pass Labs X5 power amp that has never been installed (boxed up for over 20 years). I asked for suggestions about powering this unit up after being stored so long. The best suggestion was to contact Pass Labs. I did and they were very helpful and offered to (for a price) test it for me but I think I'll do it myself when I have some time. I was originally planning on using it myself but I think I'll get rid of it. Anybody here have an Idea of what I should list it for here if it works?

@philliprcook Some folks recommend gently powering up long-unused equipment on a variac at 30V for 12 hrs, 60V for another 6 hours, and on. I may try this on some components I have coming out of storage, but maybe some folks here have done it?

I use a McIntosh MC7270 amp with a C 712.. These units are easy to get serviced and are built to last a century.  The C 712 recently needed a new power supply.  I sent it to George Wilson and had it back in a week with a full tune up. 

Don’t let the fear mongering get to you, who cares how old an amp is ? Secondly who cares if the company is still in business. It’s electronics virtually everything is replaceable outside of cosmetic i.e. case, buttons, knobs, that sort of thing. Exceptional quality equipment of the past when you’re talking amplifiers would still rate higher end today. Research find the end game, restore, financially you’ll come out way ahead IMO, has for me many times over.

Cheers 

Not every amp can be repaired (or upgraded) without the original schematic. So the who that should care is anyone buying a 20+ yr old amp whose manufacturer is out of business.