Here's my half-pennyworth.
Even if the MK signature is real, does the written statement above it look like MK's handwriting? I'd venture not.
I would be amazed if MK signed any blank documents and even more amazed if a manager of his (even a tour manager) did so either.
"Signed, Sealed and Deliovered" suggests it is from a legal document - originally at least.
"Certified to by a true copy" should read "Certified to be a true copy" but, even in its correct form, the phrase suggests that this is not the original document (though possbly not a photocopy of the original).
Finally, we only see the end of the document, not the whole thing.
My conjecture is that someone (Alan Woods, presumably, but maybe a friend of his) got hold of "a true copy" of some legal document involving MK's accountants, took the final section (that is, the bit between the typewritten text of the original legal agreement) and inserted the wording we see above MK's signature. I'm quite preapred to be wrong about this but the above are my thoughts.
The oddity about this document is that it seems to have been folded and sealed with wax at some point. I'm not sure about this but the only documents I've ever seen sealed with wax came from about 100 to 200 years ago, though it was a practice used earlier than that and possibly later.
I wonder if someone (possibly at the accountants) came across this document (perhaps it was put out for shredding or something), kept the end part of the document, added the phrase above the signature, folded and sealed it with waxand passed to Alan Woods as some kind of joke. Just a thought.
