I agree that it is some type identifying tag, but I don't necessarily believe the nail was originally in that position. It's not logical to me. Sometimes during the past 100 yrs.( or X amount of years that it is old) someone put the nail in the hole backwards, perhaps for storage. Back during that time people saved and reused just about everything. Maybe the tag and nail were removed, and before putting it in storage, someone slid the nail in the hole to keep from loosing the nail. Just a thought.

Breezie