Stage 1 (Posted Co-ordinates)
High on the wall is a date - ABCD
2nd stage is at
51.(B+C)-(D).(B/D) (A+D) (B-D)
00.(B+C)-(A+D). (D) (B-D) (A)
Look for a blue sign with numbers
E
FGH
Cache is at
51.(B+F).(A+B)(G)(E)
00.(C+F).(A+F)(C)(D*E)
APRIL 2021 - PLEASE NOTE PUZZLE UPDATED AND FINAL MOVED SLIGHTLY. IF YOU HAD OLD COORDINATES TAKE 24 FROM NORTHING AND 26 FROM WESTING