Just to let everyone know, one of our Lost My Stuff Group volunteers did go and help the owner search for this ring, unfortunately they couldn't find it. The location was a very difficult place to hunt – a mound of leaves on a hill behind a potting shed, intermittently populated with poison ivy.
The owner sent me a note after their search to tell me the volunteer who came by was very "thorough, knowledgeable, conscientious and made a good search", saying it was a tricky area to work, and that he was quite satisfied with the effort that the volunteer had made.
He also indicated the volunteer left him some information he could use if he decided to continuing the search more himself.