Board Thread:Questions and Answers Forum/@comment-173.175.209.242-20150305065740/@comment-1158256-20150305082613

The Murmur weapon can only be obtained once per character, by completing Eris Morn's quests. Also the Stranger's Rifle is once per character on story completion.

To get another of either of these items, you would have to delete the character and recreate it.

Dead Ghosts can only be collected once per username, but they don't give you a combat bonus.