my guess is they are peices for a master key to crypt , similar to the master key of howling stones i have also been looking for a dorp or ground spawn of a Container similar to the one in howling stones for a master key combine
I have gotten these three items. Undead Froglok Spine, Small Froglok Bone Vile, and Scroll of the Dark. All of these drop in crypt. I think these might be a part of a quest for a key for the crypt. Havent found anything else yet. If u find any information plz post it.
I have one of theese also. Been looking for information on it. Searching for unfinished quests that have something to do with seb. Haven't found anything yet.