Alterations on Dr. Octopus' face and Spider-Man's legs by Jack Kirby. The unaltered cover was published in various reprints, including the cover to Marvel Tales # 148. (additional information provided by Nick Caputo)
Jack Kirby redrew part of Spider-Man's figure on the splash page. Info per Nigel Kitching, as published in Jack Kirby Quarterly.
Story concludes on inside back cover.