You will find them insisting that it has not been authenticated, nor has it been debunked. This is Orly Taitz's own position.
The real issue, repeated many times on these threads, and just now by you, is as follows.
Does the B/C match other B/Cs of the same period?
Does the book and register number match a record in the Birth registry?
And do the details in the registry match?
These items alone are important. Any assumptions the brownshirt media might have about Mombasan registration workflow and letterheading fifty years ago are simply not relevant to the discussion. Only the primary sources matter.
People are missing the point on this one. It doesn't matter whether it is real or not. What we now have are two conflicting pieces of digital evidence ( Obamas COLB and the Kenyan BC ). The only way for the judge in CA to resolve this is to order discovery of the actual hard copies from Hawaii ( he can have the State Department request them from Kenya, but in all reality, they don't have to comply ). The main reason for producing this document now is to force production of the Hawaii BC.