Hi Ray, Do you have a copy of his obituary? If not, contact Random Acts Genealogical Kindness. Go to raogk.org, read guidelines, choose California and choose ALL for the county and look for Brenda.
If that doesn't work, contact the Contra Costa County Historical Society, cocohistory.org/frm-start.html .
I assume you have access to Ancestry since you posted the Brown Family Tree. When you look up his social security info on ancestry, a box appears which shows that info. At the bottom of the box is "Learn More". Click on that and it will tell you how to order a copy of his social security application which will list his parents and I believe where he was born.
You can also use RAOGK to find out if he was married in Contra Costa County. Successful Searching!