Yes, but something like birth certificates would be printed on forms, so it’s not out of the realm of possibility, knowing that they would need a lot of them, and to make them consistent, they would all be stamped with the Republic of Kenya the minute they started issuing them. At any rate, the ones recorded before and after, can be checked to see
This is only wikipedia, but they state:
“On June 1, 1964, Kenyatta became President when he successfully had Parliament amend the Constitution to make Kenya a republic with his office becoming executive President: the head of State, head of Government, and Commander-in-Chief of the armed forces.”
Is this not so?