Subsitution key on f1r

[exlipsiae]

On the right, there is an alphabet with a shift. It could also be used...

I have tried this as well. Generally the results witht the 3rd column look even less promising, since there would be no "a" in the plain text. Also I believe that the 3rd column was more "playing around" by shifting the 1st column key, when it became clear that this was not working. 
But the main problem as with any substitution is still to identify what particular word might have casued Marci to assume this key in the first place. 

Given that the Voynichese column has unique characters that don't appear elsewhere in the manuscript at all (at least not in the folios we have) while some existing characters don't appear in the list, I assume this column was there before Marci and is likely part of the original manuscript, and the upper right red weirdo is the heading of this column. What Marci did was only to write Latin letters next to the glyphs. Maybe, for the first attempt he made a mistake skipping a character and then produced another column.

That cannot be ruled out either
But it would be very disappointing   and still leave the question as to why the original author would leave this arbitrary list of symbols

What is more, I'm not at all sure this was an attempt of solving the cipher via substitution. This would be a very strange attempt, its failure would be obvious immediately just looking at the Voynichese on the same page. It could be just a way to give the glyphs an easy to understand names (similar to what EVA does nowadays), because properly writing some of the glyphs is not easy and giving them names would simplify the communication about this script. In this case writing this list in a permanent ink on the first page would make sense.

You're right, we don't even know if it was intended as a substitution key at all.
The EVA comparison is very interesting, too. But wuldn't the be a strange way to go about it for the same reasons? If the goal was a basis for easier transliteration (and maybe copying) of the manuscript, wouldn't you want to assign a letter to all symbols? As it stands, it doesn't even cover the first page. Furthermore, what would be the point of the 3rd column in that case?

Again, my thinking was that if Marci had an idea what one spcific word or maybe sentence of the manuscript might mean, he may have tried to derive the substituion alphabet from it. After trying to apply this substituion to the rest of the text he soon would have realized that this isn't working, maybe try plaing around with the shifted version in the 3rd cloumn and then give up on it. 

My goal was to try and find this one specific word or phrase that might support this. 

The handwriting of the letters on You are not allowed to view links. Register or Login to view. may be compatible with Marci's, but they could have written by someone else -- like Barschius.

Also true. For my intial post I just went with Marci based on the expertise of Lisa Fagin Davis. If there are other clues that point away from Marci, that might well be the case.