It may be the initials of whoever signed the document (secretary of state) and the typist.
The initials at the bottom of documents was a very common practice when people used typewriters. Mr. Boss Williams would compose a letter and Mary Secretary would be the one typing it.
The typed letter had the initials BW/MS at the bottom to indicate who did the work.
After some checking, I am advised that the initials are a control reference designation of the person/group within the Authentication Unit of the Secretary of State‘s office who worked on the document. In current practice, the Apostlles are electronically produced and the signature of the Secretary of State is machine stamped under the control of those persons.
It has no significance as to the document itself. I hope this helps.