The ones I knew of are long gone. I've seen a bunch of old pro mdedium format gear in Steve's Camera Repair, Culver City but not sure if they are display or for sale. In general, though, the vintage camera scene in SoCal is fairly bleak.
Dexter's Camera and Hi Fi on Main St in Ventura has more old camera gear on display than just about anywhere, 4 shelves on at least 30 ft of wall. I don't know how much of it is for sale and how much is the owner's collection. They'll even have a varying selection of darkroom supplies and equipment.
“You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live.” - John Galt