The claimed Voynich page

[Bernd]

But you said later that you had to correct for perspective distortion?  That is an important detail.  Direct tracing (of the original, or, more likely, of a printed digital image) through a translucent vellum would of course introduce no distortion.  Use of a camera lucida may introduce some perspective distortion, depending on the position of the original and the copy.

The Beinecke scans have some perspective distortion (that any image editor can correct for), but also a more irregular distortion from the vellum not having been flattened out for the imaging.  As a result, the image is usually compressed to some extent near the binding gutter, or near the fold between two panels of a fold-out folio.  Did you see any sign of the latter in your overlay attempt?

I'm not 100% happy with my solution, but here's a gif showing Fabrizio's original image and the way I had to distort and rotate it to fit the 2004 scan of the VM.

   

It required a lot of shearing to the left in the lower left corner. There's also some clockwise 3D rotation involved. Not sure what to make of that. Maybe a simpler solution could be found, I guess it should be possible to have software align key points of the two images in the most parsimonious way.

It is evident that the copyist did not know the Voynich alphabet, and thus several glyphs were distorted beyond recognition.  
He also seems to have struggled with the writing instrument, because the ink color varies inconsistently and the thickness of the strokes varies in an "unnatural" way.  
In fact, the letters do not seem to be drawn with a quill pen, whose square tip creates characteristic traces.  Maybe with a steel pen?

I think an interesting observation is that the VM was created by a capable scribe who was a terrible illustrator while this copy was obviously made by a capable illustrator who was a terrible scribe. The lack of attention given to the text is baffling. Obviously the creator had no idea about the Voynich alphabet, but even beyond that he carelessly mixed up the letters and made very amateurish mistakes - on top of a questionable aesthetic quality of the text. In stark contrast to the vastly improved image. So far I have no idea when this could have been made, or how, or why...