The final cache location is; S34 4A.ABC, E140 3C.CDE
Where;
A is the number of words on the second line on the plaque.
B is the second digit in the first year.
C is the number of times the word "Ghost" appears ion the plaque
D is the third digit in the first year
E is the number of times the word "Allen" appears on the plaque.
I hope you enjoy visiting the Ghosts of Allen.