Hi c.j., Another source of information would be George's or Gail's obituaries. I couldn't find any exact death date for George which you'll need to find his obituary.
I found a Gail M. Agnew Residence on file at Social Security: El Cajon, San Diego Co., CA Born: 13 June 1936 Died: 2 Aug 2001 Her soc. sec. # was assigned in Arizona in 1970. Source: Social Security Death Index.
I thought that Gail might be his wife.
There is no guarantee she died in El Cajon. I can't find the California Death Index for 2001. Maybe not published yet.
You can contact the El Cajon Branch Library,sdcl.org, click on Contact Us or AskALibrarian. They have obituary copies but are "thinly staffed" and it can take awhile to receive a copy. Successful Searching!