Feature logo credit from http://kleinletters.com/.
Inside front cover.
The script and art credits come from Tom DeFalco in Andy Mangels' "Super Jrs. vs. Superkids: The Many Mysteries of DC's Romper Room JLA" in Back Issue #76. Mangels also reveals that the story was likely originally prepared for release as an issue of All-New Collectors' Edition in late 1977.