Where are the letters penned by Voynich?

[ReneZ]

Do you have some data to back that up? Statistics? Chance of forgery is x % and chance of "real medieval undecipherable badly painted manuscript" is y %?

Some years ago I estimated that x % is probably of the order 0.0001 %
But it was necessarily a rough estimate, and I believe it to be on the high side.

For the MS to be a fake, three independent things had to be achieved by Voynich:

1) Find an original ex libris of Tepenec in order to put it in the MS
2) Find some original old parchment, including large foldouts.
3) Read the Barschius letter that was actually hidden by the Jesuits.

An original and usable copy of the Tepenec Ex libris was first found in 2008 by Andreas Suzler, as the result of an internet search of a digitised card catalogue of the Prague national library. There's no record of Voynich ever having been in Prague, but it is clearly not impossible that he could have seen it. I put the probability optimistically at 1%  (i.e. 1 in a 100).

Original parchment may have been found by Voynich, but this MS has foldouts, one as wide as 5 panels of text, and one 3 panels wide and 2 panels high. As Rich's web site demonstrates, he could have sold the raw unused parchment for a good price, so I estimate the chance that he found this set and used it to create a fake as 1% (again 1 in a 100).

The Barschius letter is the biggest problem of all. The Jesuits were continuing to hide their archive material in which it was included and it probably was stored in a different place. Remember, the Voynich MS doesn't actually exist in this scenario, so why look for the Barschius letter in the Marci-Kircher correspondence in the first place. A very optimistic 1% here (1 in a 100).

The probability that all three independent things are true is the product of the three probabilities, so 1 in a million.