I hope they are able to trace the line of ownership back to the fellow who took it
I doubt this will ever happen - even after 13 months of investigation as per the story.
It's probably been through more hands than a deck of cards in Vegas.
Winding up at a 'barn sale' pretty much sums up it's post theft history.
It's just lucky someone with knowledge of historical artifacts found it or it would have likely ended up over someones fireplace - or worse.