Marci's letters to Kircher, revisited

[Psillycyber]

It is not clear from your post whether you are aware that here are 30+ more letters from Marci to Kircher.
They are all at Philip Neal's web site.

I do agree with you that we can't be sure that the 'schaedata' mentioned in 1640 are copies of the Voynich MS. It is tempting, but not certain.
Note that neither the web page you quote, nor Philip Neal's translation and comments actually state this.

Yes, I am aware that there are many other letters on Philip Neal's excellent website.  I thought about going through ALL of them with fresh eyes, but I haven't the time right now.  

If I recall, of them, the 1637 letter from Barschius to Kircher seems like the surest bet for a description of the VMS, which makes me wonder...had Barschius not talked to Marci about the book at this point?  (We know, if we assume that the 1640 letter is also about the VMS like many researchers assume, that they had talked about the book as of only a year later at the very least).  Because, why didn't Barschius talk about the rumored provenance of his book at this time of which Marci was aware from Doctor Raphael?  Why did it have to wait until many years later in 1665 for Marci to mention the stuff about Rudolf II and Roger Bacon, etc.?  The provenance is one of the most important things about a mysterious, unreadable document, and I don't think you need to be a professional historian living in the 21st century to appreciate that!  Why didn't Barschius mention all of what should have been relayed to him from Marci about Doctor Raphael's rumors?

Perhaps Barschius didn't want to seem flighty or given to gossip-mongering or latching onto far-fetched ideas.  So then, I wonder why Marci would have ended up deciding differently to tell Kircher about these rumors in 1665.  Was Marci getting desperate to bring this book to Kircher's attention, and decided to bring out all the stops, even if it made Marci look like a bit of a loony in the process?  (Hence his distancing himself from the rumors with the "I suspend judgment on the matter"?)

The 1665 letter just doesn't feel like it fits chronologically.  It would make much more sense if it had been chronologically swapped around to have come before the 1640 and 1641 letters.