...which is inadmissible in evidence under Rule 902 (3) of the Federal Rules of Evidence.
That is not what 902(3) says.
Extrinsic evidence of authenticity as a condition precedent to admissibility is not required with respect to the following:
(1) Domestic public documents under seal...
(2) Domestic public documents not under seal...
(3) Foreign public documents.
- A document purporting to be executed or attested in an official capacity by a person authorized by the laws of a foreign country to make the execution or attestation, and accompanied by a final certification as to the genuineness of the signature and official position (A) of the executing or attesting person, or (B) of any foreign official whose certificate of genuineness of signature and official position relates to the execution or attestation or is in a chain of certificates of genuineness of signature and official position relating to the execution or attestation. A final certification may be made by a secretary of an 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 official documents, the court may, for good cause shown, order that they be treated as presumptively authentic without final certification or permit them to be evidenced by an attested summary with or without final certification.
(My emphasis added)
Nothing in that Rule keeps the Kenyan certificate out, and gives several opportunities for it to come in as proper evidence.