Vintage audio gear repair shops in Bay Area?

Absolutely!! The Sound Well in Berkeley. www.thesoundwell.com
One of the few places where honesty reigns. Sales of very nice vintage equipment with an outstanding service dept. Prices are as reasonable as you'll find anywhere. I personally check their website for vintage equipment on a weekly basis. I'm a former McIntosh dealer and I couldn't recommend them more highly.

You could also try Nick Gowan at True Sound in Campbell.
He is a most excellent technician!

Nick's email is

gowan@tsound.com

408-370-7578

Been working with Nick since around 1980; he is quite reliable and if he recommends something it is the Right Thing.