I really recommend checking out the bookstore under St Mary's Parish Church inbetween Crouch End and Muswell Hill. They had a flood recently and are looking for donations to replace ruined stock.
I think its fair to say my Scott Bookshelf is pretty glad these beauties were saved from said flood.
(they also had a bunch of Buffy books and I got an amazing book about Witchcraft and Demonology. What I thought was going to be an amazing goth bookhaul turned into an amazing Polar bookhaul. Day of book win!)