Read
this thread over from August 1999 and provide a summary... something something about "Glowing Stein" being the original reward for the quest, but then being changed to "Stein of Moggok". Reports on TEST about it being a weapon currently and 'hoping' it stays that way. Something else about how if you unequip it then you can't re-equip in offhand.
I'm too tired to make heads of tails of it now and have never done the quest and unfamiliar with the item.