Elwin Ransom
Elwin Ransom may be based on C. S. Lewis' friend J. R. R. Tolkien ("Elwin" means "Elf friend" in Anglo-Saxon), though he seems to have autobiographical elements. In "That Hideous Strength" Ransom, with his royal charisma and matter-of-fact breezy acceptance of the supernatural, appears less like Tolkien than like Charles Williams (or some of the heroes in Williams' books).
Dorothy L. Sayers
Sayers was a good friend of C. S. Lewis and several of the other Inklings. On some occasions, Sayers joined Lewis at meetings of the Socratic Club. Lewis said he read "The Man Born to Be King" every Easter, but he claimed to be unable to appreciate detective stories. J. R. R. Tolkien read some of the Wimsey novels but scorned the later ones, such as "Gaudy Night".