As an artist/writer, I wouldn't use my first drafts and sketches in my final work - I get them worked out, notes, scratch-outs, additions, etc and THEN put them to the final work.
Certainly, many ancient manuscripts exist as final, edited 'editions sans notes, corrections - n'est-ce pas?
I know, put the thing on the internet and let the entire wired human race try to decipher it. I am willing to bet that someone in this world can read it.
People do such a cleanup only when they expect other people to read the manuscript. Can it be said about an encrypted work, with no known key or even a hint of a key?
And if the manuscript was NOT meant for distribution then there is no reason to bother cleaning it up. A scientist would rather prefer the unedited version because it contains more information.
This means that the book is not a lab journal. If real, it can be an essay on some alchemical research - no problem with that. But there is no key anywhere; you can't distribute such a complex book if nobody can read it. And if you have readers you must have other materials from which they learned the writing. These are not prehistoric times, documents were well managed at that period and we have tons of them. We'd see a margin note in this language *somewhere*. Nobody would even bother studying such a complex language if there is no body of information in it.
This disconnect is exactly what pushes many researchers into belief that the manuscript is an ancient fake - it just doesn't fit into anything. We'd be better off if it was laser-engraved on sheets of 99.999999% pure Praseodymium - at least we'd know that it's not done by humans. But this book is certainly a product of a human hand.
The script itself is fluid and confident, with clean strokes. There doesn’t appear to be much evidence of pausing or indecisiveness there. It’s not particularly well ordered or linear upon the pages, however. The weight of the strokes varies from page to page, haven’t looked closely enough to really see anything that might be significant about that. Somebody appears to have been accustomed to writing it, whatever it is, but that someone was not too caught up in appearances, otherwise there would be some semblance of composition and the script would be much better planned and thought through for a more organized and polished appearance.
The illustrations are another matter. They’re irregular, somewhat disordered and fanciful in an inelegant manner that I would deem nearly unskilled, almost childish. Sort of like the naive painters that art buffs would recognize, a certain radiance and vision welling up with very limited talent or means to render it, but the radiance and vision wins out over the lack of technique and training, making it compelling to view despite the amateurishness. There is clearly some vague knowledge of the internal workings of the female reproductive system, not uncommon among artists but this isn’t really an artist, maybe an aspiring one. There are also circular graphics shown repeatedly, with segmentation of 8 or 12. Significant of the zodiac, I’d think. There are also a few characters in the script that might appear to be familiar along those lines.
I have no way of figuring out myself whether or not this writing might be a “language” or not, or what the specific point or points the creator of this might be attempting to record or communicate. That has to be left up to the “experts.” If it’s not an antique hoax, I’d suspect someone involved with alchemy perhaps. It was highly fashionable in some circles during the era in question. There are several so-called books of magic that originated along about then. Also, the Slavonic Book of Enoch and the Greater Key Of Solomon spring to mind. But these weren’t encoded in some unknown script, if that’s actually what this represents.
As a result, all I can say is, if this is something genuine, it really wasn’t intended for wide distribution. More care would have been taken with it if so.