A foreign official record, or an entry therein, when admissible for any purpose, may be evidenced by an official publication or copy thereof, attested by a person authorized to make the attestation, and accompanied by a final certification as to the genuineness of the signature and official position (1) of the attesting person, or (2) of any foreign official whose certificate of genuineness of signature and official position either (a) relates to the attestation or (b) is in a chain of certificates of genuineness of signature and official position relating to the attestation. A final certification may be made by a secretary of embassy or legation, consul general, consul, vice consul, or consular agent of the United States, or a diplomatic or consular official of the foreign country assigned or accredited to the United States. If reasonable opportunity has been given to all parties to investigate the authenticity and accuracy of the documents, the court may, for good cause shown, (1) admit an attested copy without final certification or (2) permit the foreign official record to be evidenced by attested summary with or without a final certification.