So, thinking some more on The NECRONOMICON and other faux-books such as THE RED BOOK OF WESTMARCH, I was reminded of something Dr. Tim Machan said in a colloquium at Marquette back in the late ‘80s (prob. ’88-‘89). Dr. Machan was a medievalist, a specialist in Old Norse literature who came too late for me to take any of his classes but stood out as being the only member of Marquette’s faculty to take part in the 1987 Marquette Tolkien conference with his excellent piece on VAFTHRUTHNISMAL and RIddles in the Dark.
One of the points he made in his colloquium was to state that, before the advent of printing, there was no such thing as two copies of the same book. Despite the best efforts of the scribe, a copy would introduce errors. Passages would get added, passages would get dropped -- sometimes by oversight, sometimes deliberately. Comments written in the margins had a way of working their way into the main text of the next iteration, while passages that had gotten garbled would be 'fixed' as best the scribe cd manage.
And of course that's in cases when the scribes were trying to be faithful, which was not always the case. Sometimes the scribe thought he knew more than the previous scribe about a particular point and would improve it. Sometimes he was right, sometimes not.
Add to this that the creation of a medieval tome was an expensive business, comparable to buy a luxury car today, and the fact that there were so few copies of medieval texts; only important things got written down, and only the most important among those would still be considered important enough a generation or century later to be copied once the original started wearing out.* And in the case of a book like THE NECRONOMICON, it has the added disadvantage that it's written by a madman and copied and read by those who are either crazed in the first place (or they wdn't be drawn to its contents) or are driven mad by the extended close contact needed to hand-copy the whole.**
In the case of a benign work like THE RED BOOK, here too we know that the content differs from copy to copy: that the Westmarch (Shire) copy includes material not found in Minas Tirith (Gondor) copy and vice versa. So even where great care is taken to make a faithful transcription, still material gets added and dropped (we're told that most copies omit BIlbo's TRANSLATIONS FROM THE ELVISH).
In any case, another element to consider when conceptualizing what THE NECRONOMICON was like, or expanding the range of what it could have been like. Ironically it supports the original treatment in early editions of the CALL OF CTHULHU game rather well, where a curious Investigator cd pick up any of the major Mythos tomes (NAMELESS CULTS, MYSTERIES OF THE WORM, the NECRONOMICON Itself) and hope to find among its jumbled contents a passage relating to almost any aspect of the Mythos; later attempts to identify the specific contents of a given tome cd actually undercut an accidental bit of verisimilitude.
--current song: "Powderfinger"
--current reading: Ryken's Wade Center Hansen Lecture expanded into a book
*for some idea of what didn't survive, see Wilson's THE LOST LITERATURE OF MEDIEVAL ENGLAND
**things are a little better when it comes to printed books, since typesetters were notorious for not being able to read the texts they were printing