Kromrif bones are apparently part of a set of new Skyshrine bardic instrument quests (revamped SS went live on Legends recently). Bones + cured brontotherium hide = new drum!! The other pieces you have found could be related as well.
More at http://pub118.ezboard.com/feqdivabardsofeverquestfrm1.showMessage?topicID=6434.topic
Toon Minstrel of Ayonae Ro "I'm not bad, I'm just drawn that way..."