Hi Mickey, I found John R. Walker on Calif. death Index. It said he was B: 12-11-1901 in Louisiana D: 12-31-1968 at 68 Years of age so their birth date is off, also last place of residence was listedas Imperial, County, CA. Winterhaven is just on the edge of Yuma, Ariz. but on Calif side of Colorado River. They listed his SSN# as 700-16-9443, so I tried the SSN death Index but could not find him. They listed 142 John Walker's in CA. but none matched dates or place of birth, death. Mothers Maiden name was listed asKERNER.
You might try Imperial Co. M/B for a lookup.Best of luck Roy in San Diego.