Thanks, everyone. My daughters are 6 and 10, and we went out together this afternoon. They were thrilled when this dime popped up, tired of all the pull tabs and corroded pennies!
My friend and his son were there, too. And I think we have another that is "hooked." We played in that park as kids, and so did our own parents. Nice to think this merc lay there the whole time without any of us knowing.
Probably more down there. I've got to go dig it all up!