I can give you a description of the fellow who took the book, as well as the pokemon that was with him.

*which, given that Sion hasn't completely lost his edge, means that if Lance accepts the offer, he'll get some pretty decent info on the guy's height, build, what Sion could see of his complexion, as well as any details he can think of that might help distinguish the Clefairy in question from others...*