OLD CEMETERIES OF SAN JOAQUIN COUNTY CALIFORNIA VOL II RURAL CEMETERY, compiled by San Joaquin Genealogocal Society 1962, page 215: Hannah Willis is buried in Stockton Rural Cemetery ...8-19-1891, aged 52.
HISTORY OF SAN JOAQUIN COUNTY pages 496-497: Beautiful bio on George Willis and a full page picture of him.
STOCKTON CITY DIRECTORY 1937, page 138: GRAY, Robt (Alice) carp h end of Robertson.
My books are too old to bend and scan. You can get the bio and picture through San Joaquin Genealogical Society asking for researcher Melinda and Charlie Lambaren (they charge a minimum fee)or you can email the downtown Stockton Public Library..using their website..looking for their reference librarian's email.Another place in reference to burials is Stockton Rural Cemetery located at 2350 Cemetery Lane, Stockton, CA ..mailing addressd P.O. Box 241, Stockton, CA 95201
I tried to copy and paste their emails on this but lost this to you when atempting it.
I couldn't find a band that you mentioned.
Good luck. My work is done...can't do anymore for you from my home.