I have never actually seen a document. I was told by a couple of R & A members that MacKenzie had helped to formalize some of the championship hole locations, but this could just be hearsay. For sure, they've been playing championships there since well before MacKenzie's time.
And for sure, at this point, they're familiar enough with the course that they don't go back and look at the document, any more than I get out my plans in the middle of constructing a course.
If it isn't in Scott M's book, then it probably doesn't exist.