It occurs to me that Call of Cthulhu would have to work a lot differently in a modern setting since there's not really such a thing as a rare or esoteric book anymore. You're one google search away from the Dead Sea Scrolls, the Popul Vuh, the Gospel of Judas, the Enuma Elish, the Book of the Subgenius, the Zohar, the Emerald Tablet of Hermes Trismegestus, Revolt in the Stars, the Ars Goetia - whatever you want - and I'm pretty sure the Necronomicon and the Book of Eibon would be no different if they were real