I noticed at the end of the letter column above, Bob Rozakis said there was to be a 72-page All-New Collector's Edition starring the JLA written by Gerry Conway.
That never materialized, but does anyone know what story was planned for it and if it was simply split up and made part of the regular JLA title?
Rozakis says "later this year" in this column from JLA 160 (Nov 1978), which was on sale in August 1978, but DC had basically stopped publishing tabloids by then.
Could it have been the 3-part story where the Secret Society of Super-Villains switches bodies with the JLA (JLA 166-168)? This was the story that was referenced in Identity Crisis.