That's a very nice use of "treasure," with Harry being oblivious to the treasure living and breathing in front of him until the very end. I, too, am interested in how they had become partners in the artifact-gathering industry. Whatever the backstory, I'm glad the chance to work together gave Harry and Snape a chance to get to know each other, since I liked the easy companionship they have in this story. Great ending too. I daresay their treasure hunting trip was in fact successful ;)