Generally speaking (with regard to 1.0's anyway); if it's a subquest of the epic (SK armor, Mage cloak, the Paladin book, the chanty spoon, etc...)

Now can't speak about 1.5's; but I'm sure they followed the same logic. Also, if the item is used in another quest (like the paladin book, SK armor, etc...) then the items are definitely droppable. Generally, the only parts on FV that are no drop; are the parts that tie directly into the Epic itself (ranger globes, wizard sticks, etc...)