I'm in the north bay and I've never used anyone local to service UG, I send stuff in the mail. I know the building you are talking about, but I'm not sure if there are people there qualified to work on a Tri. You could search the entire bay area (IIRC there are two main places that come up for vintage service, one in the south bay I think, can't remember where the other one was located).
Anyhow I think you will have better luck researching on the internet and phone, than with your feet. Although if you are going anyways, there's no harm in asking around I suppose, and getting a quote. But I would want to know how many Tri they have serviced and when was the last one.
Side note, your Tri is beautiful, but I think one or both hour/minute hands are wrong? (I can't tell if that leaf hour hand might be stock, it looks a bit odd and I would expect dauhphine, see below) It would look much better with correct hands, and a new crystal.
A quick search for 12268 shows both leaf hands (early case serial) and dauhphine hands (late serial, close to yours), I assume dauphine would be correct. Not sure how easy it is to get a set of correct hands for a cal 481, but I would search and have them swapped at the time of service if you can find something. Even leaf hands would look better than the current mismatch IMO.
good luck, it's a lovely Tri !
This one is serial 1129206, much earlier than yours....
This one is serial 1410739, closer to yours, also with the faceless moon, and I think a good reference for what yours should be....
