The Modern Forgery Hypothesis

[Mauro]

In fact, the ENTIRE evidence for the provenance of the VMS between ~1438 and 1912 hinges on that letter describing the book B and no other book.

Well, no. The first evidence is the C14 dating, coupled  with the fact that vellum was generally used a little time after it was made (I'd guess in a few years). It's not impossible for pristine vellum to sit unused for ~500 years, but it's quite improbable, expecially in the quantity needed for the VMS. It's not enough to say 'he might have found 500-years old pristine vellum when he bought a whole library': unless you can demonstrate he actually found pristine vellum there or that at least it was highly probable to find it, it's just an You are not allowed to view links. Register or Login to view. hypothesis.

It's also not impossible that a forger will use unusual foldouts, then bind his forgery out of order and add additional quire marks, add arcane marginalia and doodles, then add stains, damages, colour transfers etc. in so good a way to be undistinguishable from what usually happens to a manuscript during 500 years of history, then cut away pages, then replace the cover and rework the binding... But all this to happen is, again, quite improbable.

The Baresch letter is fully expected on the hypothesis that the Voynich existed when he wrote, it's also fully expected if some other similarly unreadable manuscript was involved too, of course, but we know the Voynich exists and has the right characteristics, while we do not know of another comparable manuscript which could have been referenced by Baresch. Occam's razor favors the first hypothesis (even if this is a rather weak evidence compared to C14 and the overall status of the manuscript).

Add in the Tepenecz signature, then the fact he wanted to sell the manuscript as a Roger Bacon work but did not put in the book even a hint of it being Bacon's (microscopes in the recipe section are in the eye of the beholder, imho), etc. Everything we know is explained quite well by the hypothesis the VMS was penned in the XVth century, while the hypothesis of it being a XXth century forgery requires a lot of improbabilities to be overcome, that's the harsh reality.