Immersion in history ping.
With a sprinkling of legends. Probably as authentic as the "James" reliquary.
That 4th Century part smacks of the purveyors of pieces of the "True Cross".
Mind you, I'm not implying that the church authorities were involved in a fraud, but rather perhaps they were duped into buying the relics from a con man. Of course, after the passage of 17 centuries, they now really are, rather ironically, relics!
Amazing of the things discoverd these day, I think a message is being sent to us.