There's nothing else of note in the chest of drawers (in Closure's private space), other than the clue scroll. What does Relomia (in Draynor) have to say on the matter?
Have you unlocked the Closure's robes cosmetic override outfit?
EDIT: Opening the casket should give you (swap to) the ghostly undergarments object, which if you click on that it is deleted and you unlock the cosmetic override. (Am thinking perhaps you just missed the unlock message?)