If I have to read "gunmetal gray, double-breasted suit" one more time, I might go crazy. Beyond that I really found this installation of the Ghost and the Haunted Bookshop series intriguing and easy to follow. A fun Gossip Girl-esque cast of possible murderers with just enough secrets to keep both Penelope and the reader on their toes. 
Also, after having read one of the later novels, I loved finding out the vackstory behind the Buffalo nickel. 
I'm a little wary of this romance still but the lyrics "my beloved ghost and me, sitting in a tree" keep running through my head during their one-on-one scenes so I guess they're growing on me.