The original has been found for John W. Campbell’s famous story “Who Goes There?”, a 1938 Lovecraft-alike tale about a team of scientists in Antarctica and their horrifying encounter with a shape-shifting alien entity. Campbell’s unpublished draft for that, known as “Frozen Hell”, had 45 pages of unused material. The original is now set to be published in 2019 by Wildside.
Science Fantasy Review for Spring 1950 lists “Frozen Hell” as part of a forthcoming Campbell collection, but it seems that book never made it to print. The work was recently discovered by Alec Nevala-Lee, just sitting un-regarded in an archive box, while he was doing research for his new book on the history of the famous Astounding magazine.