The 'special' weapons are better than the un-upgraded versions of the normal weapons, but they're not significantly better than the upgraded versions.
Really though, you don't have to go through that hell. The only way to really find them all is to exhaustively search the world. If you play through it again, you'll find the same drops in approximately the same place.
Annabelle drops from a seemingly random nightkin). They may appear random ( LOVE/HATE for example drops from a seemingly random raider captain.
