This image was produced for what may have been the first X-Men t-shirt, which was offered for sale in X-Men #12. The image itself was not published until it was used as a pin-up in X-Men #74. Writer (and former Kirby assistant) Mark Evanier was kind enough to confirm that the art was by Jack Kirby and Chic Stone. Check out his blog for tons of Jack Kirby stories, and tons of great articles in general! http://www.newsfromme.com/?s=jack+kirby
