They may not be in your area, but I took my Martin 12 stringer to KGB Guitars in the Pacific Art Centre, Birkenhead. Reasonable price, too. The Martin never sounded so good.
I was so impressed with their work I took my 40 year old Epiphone 12 stringer for an overhaul, and I'm very fussy who messes about with that guitar. It came back better than it's ever been since I bought it 40 years ago.
Fast, friendly, reasonably priced, expert service - with a large tidy, brilliantly equipped workshop. On the strength of the work they've done for me, I'd recommend them to anybody.