John Sampson burial record

[Genealiza]

Mansion House, San Jose: built 1850
http://digitalcollections.sjlibrary.org/cdm/singleitem/collection/arbuckle/id/297/rec/6

Mansion House, Marysville: built 1853
http://files.usgwarchives.net/ca/yuba/history/1924/historyo/chapter1327gms.txt

scroll down about 1/2 way to "Other Early-Day Hostelries"

[Foehn]

Thanks Genealiza. The dates on those "Mansion" houses tends to confirm that San Jose is definitely the place he died.
The  pioneer files re the Sampson family were largely written by Alice McHone a grand daughter of Camilla Beverly Scott (Sampson) Klein and were written such a long time after the deaths of the 3 brothers, that they do have errors in them. Alice's grandmother died before Alice was born, so stories are not first hand. Therefore I'm cautious of that information and have where possible tested it against known family history and newspaper accounts, documents etc, from this side of the world.