Perhaps if you find a person of the cloth, and a police officer that live right there, they could recover it for you! If your a crazy person (and I'm not calling you one), but if you are, a police officer is usually good at detecting that sort of thing. Both people are known to keep other peoples secret's in trust, it's part of the job. The cop and priest could watch dog each other, and the chance of both being dishonest, IMO, would be minimal. The fact that these 2 people helped you find your boxes would also add credibility to your adventure and find.
If you know of the approximate value of your potential find, just draw up an agreement between yourselves before proceeding. Remember to keep all records and emails of communications.
The best thing is, a lot of the officer's and reverends proceeds would probably go to worth while charities or programs. And of course a chunk of yours would go to me...lol.
If your sincere, I wish you nothing but the best! If your not...well...@#&% settles and cream rises.