I two Faded Velishoul's Tome Page which are both exhibiting the same behavior. Holding them on my cursor and casting identify on myself on reveals that they are in fact a "Faded Velishoul's Tome Page" but not which of the numbered pages they are.
http://wiki.project1999.com/Faded_Ve...%27s_Tome_Page
Without this mechanic working it seems impossible to research the enchanter spells Invigor and Feedback.
I probably have page 16, however trying to combine it with a page 17 fails saying these items can't be combined.