https://everquest.allakhazam.com/db/quest.html?quest=6786
It seems like the Convorteum anniversary missions have a very small chance to drop this item as extra loot, along with the two regular items from the chest, plus the possibility of augs. In short, there is a very slim possibility that four items will drop from the chest.
Edited, Jul 1st 2013 7:58pm by Braikkarrii