As a geocacher, I say leave it be.

However, IMO it would not be so bad if someone in control of the land wanted to expose the compass (assuming it is there) to keep the story of it alive, perhaps placing a marker there.

If it were my property and I was aware of the story and was sure the compass existed, I would probably expose it to preserve the history. If it was my property and someone else exposed it without consulting me, I would not be so happy.