Probably the method I used for this prop is pretty obvious. Thanks Dave Lowe. And inspiration came also from all the Necronomicons out there (too many methods to link to).
But since I knew I'd be sewing parts of this up, I couldn't work directly on the existing cover of the book. By the way...
One of the Witchfinders-General of generations past left this gruesome relic for me:
He sewed the eyes and mouth shut. Don't know why.
The binding has loosened a lot over the years.
Until I figure out what to do with it, it will sit next to the WFG guestbook.