I found a death date for Keith Bright. You might see if there is a lookup in California for an obit or death record. I also found one for Rush Bright.
California Death Index, 1940-1997 Name: Keith L Bright Social Security #: 579146229 Sex: MALE Birth Date: 16 Jul 1907 Birthplace: Iowa Death Date: 4 Dec 1973 Death Place: Sacramento
Social Security Death Index Name: Rush Bright SSN: 483-05-3077 Last Residence: 60018Des Plaines, Cook, Illinois, United States of America Born: 9 Sep 1902 Last Benefit: 60018Des Plaines, Cook, Illinois, United States of America Died: Jun 1977 State (Year) SSN issued: Iowa (Before 1951)