Right. I have found contemporary bilateral agreements signed between “Government of Kenya” and other countries. They never refer to “Republic of Kenya” in 1964.
I suggest the document is a forgery.
I think there might be a difference between a document intended for external use in a treaty with another country and one that was for domestic use within the country (a country that planned to become a republic and was in the process of writing its constitution as such). Itranslate a lot of official documents and countries often refer to their very own agencies and government offices in several different ways in the same (official) document.
We won’t know until we see other birth certificates from that date, IMHO. Btw, the microfilmed Kenyan national archives are supposedly at the University of Syracuse (New York). I don’t know what years or why they’re there, but that’s what another posted said earlier in this thread.
In 1964 would Kenya have been a member of the British Commonwealth? If so the term Republic would not have been used as the Queen is considered the head of state of all Commonwealth members. There was a movement in Australia some years back to abandon the Commonwealth nd become a republic. I on’t know if it went anywhere. I can also remember in the 60s listening to radio stations CBL Toronto and CBM Montreal for hockey games. Those stations would sign off at 1 AM by playing BOTH O Canada and God Save the Queen. (Though the announcers simply referred to it as “the Queen.)Canada was not a republic either. So I doubt that in 64 Kenya had made the decision to leave the Commonwealth.