“An early baptismal or circumcision certificate.”???
What does that prove? He is not a mohammedan?
Many mainline churches are very particular about maintaining detailed records, including baptism. The records would be timely entered by hand by the officiant and witnesses present would sign. I would assume the "early" part would refer to a baptism done immediately after birth. Personally, I would place more credibility on an authentic baptismal record in a Churches archive than I would a BC copied by a state worker.