I have no family connection, but I saw your message and I love a mystery! I thought I may be able to help and I think I can.
I found this family in the 1930 Census in Fresno, California.
Ralph E.Sr. and Harold E. were the sons of Henry and Daisy Agnew. Ralph, Harold, Henry and Daisy I.were all born in California. The census was a bit hard for me to read, but it states that Henry's father was born in Ireland.His mother Australia (????) Henry is 61years old (born about 1869) and Daisy was 50 years old, (born about 1880). Daisy's father born in Missouri and her mother in California. I have a feeling this was Henry's second marriage, so it is possible that Ralph and Harold had 1/2 siblings.
Although, I could not read the occupation for Henry, Ralph was a clerk for the Electric Power Company.
I will search some other census records and post anything I find.