Well, a US baby couldn’t be African. But a parent could. I don’t have any examples, sorry. My point is that it would have been natural for some clerk to use “African” to try to confer respectability on a black-skinned foreign national.
Not in 1961. The preferred word was Negro. And a COLB is not a birth certificate. It's merely a confirmation that a kid was born somewhere on a specific date. It's something that is issued after the fact, so the parent and kid have proof that the kid actually exists, and the parent can then use it apply for benefits. It is not a record of birth however.