To solve this multi, you will need to go into the phonebox and find the number of the phone inside. (01609 followed by 6 digits). Note this number down.
These 6 digits are A, B, C, D, E and F.
The final cache is a short stroll away at:-
N54 22.(E-F)CE
W001 18.(A-D-F)BE
The Fine Pair series was originally started by wizardsmum.
If anybody would like to place 'A Fine Pair' of their own please do, I would just ask that you let mattd2k know first so he can keep track of the numbers and names to avoid duplication.
He also keeps a public Bookmark List of this series so once your cache is published please contact him via his profile page to have yours added.