Wells Fargo is set to sell its San Francisco headquarters, part of a broader shift in the bank’s power base to the East Coast. The office at 420 Montgomery St. in San Francisco’s Financial District could be put on the market as soon as this month, people familiar with the matter said. Wells Fargo has hired as an adviser the real-estate investment bank Eastdil Secured, which it sold in 2019 and still owns a minority stake in.