It is a suggestion which could be added in the same vain as event/achievement/quest gained unique items.

Possibly in the future they could create a unique set of items that serve no purpose other than glamour if you have obtained said item appearance before.

As you stated above you prefer the way the unfinished one looks and if that's the case they could add an NPC which sells "Imitation Unfinished Gae Bolg" which would purely be for glamour sake and could only be obtained if the player has obtained the item through the quest.