Vitalsearch.com has the California Death Index online at:
http://www.vitalsearch-ca.com/gen/ca/_vitals/cadeathm.htm

There is at least one James P. Ball with a spouse (initials "LL") who died 11 July 1923 at age 71 (?) in Los Angeles (county number 70). County numbers can be found on their main page at: http://www.vitalsearch-ca.com/

This may or may not be your guy. You would have to search through the remainder of the indexes.