It is indeed intresting. As mentioned I roughtly estimated it somewhere between 7th and 13th century. As far as I know the details on the tang havent been seen/made like this since the 14th century. As mentioned the "cousin" in the relief above looks already more sophisticated. So its clearl before 14th c, unfortunatly I dont have further refference to close in a more exact timeframe.
I think I'll keep this piece for a while, so its not for sale