To find the cache, gather the following information.
The Post Box number code = SLa bc
The cache can be found at N51 30.(b-a) ([b+c]-a) (c x 2) W000 40.(b-[a-c]) (a-c) ([b x 2]-[a+c])
N.B. The telephone box has no number as it is no longer in use, except as a book swap station.
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 at email@example.com 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.