The cache is not at the posted coordinates. It is a simple puzzle cache which can be approached from more than one direction. Crossword puzzlers will have no problem finding this one.
Sounds like my little finger. But when? (standard UK date format will give you AB/CD/EFGH)
The cache can be found at N 51° (H-G)(H-A).(D-E)(D-A)G ' W 001° ED.(A+E)(A+E+E)F.
Congratulations to Mrs look-sharp and Miss look-sharp for the First to Find and Oxford Stone for a close second. (Obviously too easy!)