I wanted to keep it simple this time; there is no shaggy dog story to confuse you (you won't have to Google Tommy Kirk's filmography unless that's really your bag).
The hide is not at the posted coordinates; between the string and the square below it, you have everything you need to find the finals.
E9 87 83 F0 91 B6 A2 4D 17 D9 27 2A 6A 51 CB
Not that literal.
¿ 1 F 7 I L X 1 4
D G 1 H Q 4 B 9 B
W 0 S 1 0 X O O F
2 A H M 1 F 7 9 7
8 2 T O ∞ R Z 3 9
± A 2 M 6 5 9 4 A
3 B 4 6 2 L S J 5
µ C 0 W π 9 3 W 3
1 D 6 0 2 C 8 E ?
You can validate your puzzle solution with certitude.
Once again, I am proud to award the first finder this prestigious FTF medallion (crafted in Japan).
Props to kcmcacher, FTS and to Dr. Flonase/HackinHiker, FTF.