This puzzle is dedicated to Joshua Fanshawe-Marshall commanding officer of Hut 33.
He once got confused with the new grid system and managed to get lost between Huts 32 and 33.
To prevent this from happening again he came up with his own system.
For security reasons he transpositioned it twice.
The keys is a well known figure at Bletchley park.
The cache is not at the published co-ordinates
you maybe can find something at
S32 05.ABC E115 57.DE
You can validate your puzzle solution with
certitude.
OMHHL OLCNL NWTHH GLMAP CYASN EUEUL INDSO FSTCG ADIPY
NNSTG SNSBE NYADI AEANE ESDHN IEAOT FEIFC SLCEI ERONN
PNTVU LFSEN GYCUL CIORP TTNPE CEEEE UEVLC MEEIM SEGSS
PMGAI GSTSS HARNM EIASG SOBAB LAHID E