#8: ...
...
... er, the second #8: could this be the RING INSCRIPTION? I believe this was written out in Isildur's account of his claiming of the Ring, which may have been in a hefty tome.
Another option would be something in the Book of Mazarbul, but the text doesn't describe anything in its pages other than runes/Elvish script, and blood.
Actually, the first #8: didn't Aragorn's hobbit-hunting expedition get cancelled because the short people are garbed in MITHRIL?
Contrary to both of these: the theme so far seems to be around flags and banners, with the three known all being present at the Pelennor. That suggests that the Black Serpent of Harad may be in there somewhere, along with the Eye of Sauron and the disfigured Moon of Morgul. Not that any of the clues seem to me to point at them, but it might spark something for someone.
Continuing this theme: the Dead of Dunharrow have 'pale banners', and Elladan and Elrohir carry a silver one. And I suppose one actual guess:
#8-the-first could be the LIVERY OF THE TOWER, which Pippin wears as a guard.
hS