Ok lets think that through...
How would the WH find the *one* forger they want, without raising any suspicion?
Then, assuming they find a true expert, how do they keep perfect confidence there is no trace between the forger and the WH. (even after the disappearance) A professional forger has got to have a some experience in staying alive, and not getting caught.
Seems to me that it would be too risky, and worth it *only* if there was not someone adequate that could be controlled/trusted.
Indeed, they would opt more for “trust” than for “expertise”.
Anyone that would engage in such a huge fraud would cover their bases. And the more “professional” the forger, the better he would have set up his “insurance policies”.
They wouldn’t be able to keep him “bought”.