The cache is not at the posted coordinates but is less than a five minute walk away
First a bit of history and info.
Britains roadside Letter Boxes first appeared in 1852.
Since then there have been very many different varieties of three main kinds of box.
Pillar box types first appeared in 1852 (free standing).
Wall box types appeared from 1857 (inserted into walls).
Lamp box types appeared from 1896 (attached to posts or poles of various sorts). The elizabeth cipher is the most common as it was a long reign and a very recent one. Questions
ab= The years Elizabeth II was on the throne
cd=The last two digits of the first half location of the postbox BH??
e=If the box is a wall box=1 If it is a lamp box=2 and if it is a pillar box=3
f= The last digit of Elizabeth II's age when she sadly passed away in 2022
The coords for the final cache are:
N50 41.(A-1)(B+2)(Cx3) W2 06.(D+9)(E-3)(F+1)
maximum stealth will be required at gz in busy hours available in all weathers enjoy