The 1851 census transcription is not very accurate :-)
Name Relationship Mar Age Sex Occupation Birthplace
John SANDBURY Head M 35 M Licensed Cictualler Taunton-SOM (Victualler)
Harriett SANDBURY Wife M 28 F --- Bristol-GLS
John SANDBURY Son - 4 M --- Exeter-DEV
William SANDBURY Son - 1 M --- Exeter-DEV
Sarah
BIRT Serv - 14 F House Serv Daddiscombe-DEV
James
DICKES Sldr - 37 M Soldier 2 foot London-MID
Address: Preston St Firemans
Arms, ---
Census Place: Exeter St Mary Major
Exeter,
Devonshire PRO Reference: HO/107/1868 Folio: 366 Page: 68 FHL Film: 0221016
A John
SAINSBURY married
Harriett BRYANT in the
Bristol regn. district, September qtr 1841 vol 11 page 160. If you obtain the marriage certificate, it will confirm both of their fathers' names.