His NARA ADD Enlistment states he was Separated with no dependents. Look for CA Marriage certificate before July 1936 for more information to be able to identify him in other later records and maybe Divorce Records after 1942. Since he enlisted with not listing dependents then I doubt he named them to receive any military allotment or as beneficiary of his military life insurance.
I don't find him on any casualty lists on Ancestry. Fold3 may have something.
In 1940 CA Santa Clara County Palo Alto Township he is listed as a son-in-law in the Cardoza Household. His wife is Ruby had they have 3 children. Do you have contact with the other 2 children or their descendants? His children's CA Birth Certificates hopefully have the city or county of IN he was born, and a middle name, again to help identify him in any later records if he was not MIA and to this day still not identified as such.
If Ruby remarried after WWII look on her 2nd marriage certificate to see if she claimed divorced or widowed.