I found this as well while going through my finds. Went off as a perfect dime signal about 6 inches down at a local park. Its a mercury dime but what date ill never know..Ugly isnt it..
Put a hole in it......its the only thing that's not wrong with it.......and use it as a sinker for fishing.
Got a couple of "oldies, goodies, but uglies" like it. Almost makes me want to rebury it.......give it a fitting funeral.