The Iron Skull first appeared in "Amazing-Man Comics # 5". Created by Carl Burgos (also the creator of the popular White Streak and some character called The Human Torch), The Iron Skull ran from Amazing-Man Comics 5-22 (September 1939-May 1941), skipping issues 12, 13 & 21. He also appeared in Stars and Stripes Comics 2-6 (May-December 1941). Although Iron Skull was one of "Centaur Comics" longer running characters, he rarely ever made an appearance on the cover of the company's books, with issue 2 of Stars and Stripes Comics being his only cover appearance that I'm aware of.
Today, I'm presenting the adventure of Iron Skull from issue 10 of Amazing Man Comics (March 1940).