The original version of this cover was produced for a new Plastic Man-Adam Strange title DC planned to launch when DC cancelled plans for the Five-Star Super-Hero Spectacular dollar comic, where the Plastic Man feature was going to appear. But then DC decided to shrink Adventure to standard size and brought the Plastic Man feature and this cover over. The left side of the cover was re-done to feature the new Starman by Steve Ditko and Dick Giordano. The Adam Strange figure originally on the left side drawn by Cockrum was eventually repurposed as part of the cover of Green Lantern #136.
Notes:
Comic Reader #173 gives the story title as "The Yellowbelly File." The first new Plastic Man story is edited by Paul Levitz, either because he may have been the editor of the aborted Plastic Man-Adam Strange title (see cover note) or because DC's policy at the time was that editors could not edit their own stories.