Hi, John and Josephine are my Great Great Grand parents also.
They are inturned at the Foster City Cemetary under the last name spelling of "DuFrisne" here is the Link
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=83...

Their oldest son James was my Grandfather and if You send me your e-mail i'll send a copy of Johns Death certificate
Josephine moved to Kingsford in her later years and Died in 1946. Hope this helps... Who is your Father and Mother?
My parents are Charles and Anna DuFresne
Take Care
Craig