Credits for pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics. [August 2007]
Various intuders in the Fortress illustrated with details from Action Comics (DC, 1938 series) #241, World's Finest Comics (DC, 1941 series) #100, Superman's Pal, Jimmy Olsen (DC, 1954 series) #97, World's Finest Comics (DC, 1941 series) #164, and Superman's Girl Friend, Lois Lane (DC, 1958 series) #87.
Original inking credit of George Klein changed to match credits from Superman #148. [Mike Nielsen 5/2007]
No villain.