At the given Coords, you will find the grave of George Orchard, who along with his family spent their latter years at New pit, Paulton. Private Orchard was one of the survivors of the 'Battle of Rorkes Drift' in which a handful of British soldiers fought against the might of thousands of Zulu warriors, famously depicted in the film 'Zulu' starring Stanley Baker and Michael Caine.
To find the cache, take note of his age when he died, this will be AB, his wife's age CD and his daughters age EF
The cache can be found at N51° (E-F)(A). (F)(B+C-F)(E-F) W002°(C-F)(C). (F)(F-B)(C+B-F).