They were a Republic according to their constitution, adopted in 1963 from what I’ve read.
http://www.chr.up.ac.za/hr_docs/constitutions/docs/KenyaC(rev).doc
What else would they call themselves in the interim? They weren’t a dominion anymore. I think we have to find some other documents from the time period in order to have a sure answer.
You are citing a constitutional document that is clearly labled AMENDED in 1999 and pretending it represents the constitution as passed in 1963. I can’t believe how many people are making this same mistake. Trying to keep up with corrections here is like playing whack a mole.
The 1963 constitution has been posted many times in this discussion, the word republic does not exist with it. Kenya did not become a republic until december 1964.
You guys better be aware of Article 4!
Article 4
Henceforth shall all government agencies use “Republic of Kenya” on all official documents. Any documents issued before the ratification date shall be printed using the new name. Any doubters or dissenters of policy, now or in the distant future shall have their carcasses tied to wildebeasts and be dragged across the plains.