The Alameda County Library system has a free library edition of Ancestry.com for use in the library.
I found the 1940 census for the Serro family - clearly a misspelling -- not uncommon -- father Thomas, mother, Gladys, sons Anton and Richard. Anton is most likely Tony
The family did not live in the Sunset District but in the Portola District. There are several listing for Richard from the Lincoln High yearbook but no address.
You may want to contact the SF Public Library Main Branch
History Room to search City Directories from the late 1940's or early 1950's under the name Thomas Serra or Serro to see if you can locate a Sunset District address.