These are amazing. This artist named M. S. Corley set out to redesign all the covers of the Harry Potter series to look like they had been done by Penguin Classics in the sixties. They have such a cool, minimalist look, and really well thought out design motifs that appear in all of the covers and tie them together really well.
Click on the picture to go to his site. You can see all the other covers, plus other series that he’s done, including the Narnia books, and Madeleine L’Engle’s Time Quintet novels.