The cache isn't at the given coordinates. To solve this you need to identify what the clues below refer to, which will give you the answers you need, which in turn will lead you to the connection.
A. Allard (one word)
B. Ashes (two words)
C. Spitfires (one word)
D. Clervaux (one word)
E. Quarry (two words)
F. What connects them? (two 'words')
The cache can be found, at what some may recognise as an appropriate location, at
N54 55.Y
W 001 48.Z
Once you have identified the locations for A-F you will need to use the number of letters in each to do the following sum
Y = (E*B*C)-(D*A)-(A+E+F)
Z= ((E+F)*B)+((D+A)*C)-D
You can validate your puzzle solution with certitude.