The whole problem is that there could be only one of a certain autograph, but it's worth nothing because you can duplicate it.
It's not even an exploit or a glitch. It's a legitimate part of the game. All you have to do is craft the written book with an empty book and quill, and viola, you now have 2 copies.
Basically what 1.8 did they made it so it told you that a book was an original copy. But books prior to 1.8 that were duplicated still say "Original Copy" and if you duplicate it now it'll say "Copy of Original" so books are basically worthless now because there is no way of telling if it truly is the original.
Just out of curiosity, I still have those old skitscape and SkythekidRS autographs. Anyone got those?