Secret Society of Super-Villains made its actual debut (as opposed to the pilot story) with issue 1, My/June 1976. Gerry Conway, Pablo Marcos and Robert Smith helm the tale, and Ernie Chan does great work on the cover for this first issue. I can still recall seeing it on the rack, and it excited me no end.
While in the pilot story there was a teleporter used to bring the potential members to the base, in this story we see a variety of villains receive invitations to join the Secret Society, including Captain Cold, Mirror Master, Grodd and Copperhead.
Even Sinestro, out in space, receives an invitation through a sub-space message, and comes to Earth to check it out. We, and Sinestro, see the impressive San Francisco office tower that is being used as the Society's base of operations.
The line-up is much larger than in the pilot. It uses the Flash's villains as its core, with Mirror Master, Captain Cold and Grodd, as well as Captain Boomerang, all rogues who appeared regularly. Sinestro, being Green Lantern's arch enemy, is better able to introduce the concept that the Star Sapphire in this story is not the one who had fought Green Lantern in the past. Hawkman's enemy, the Shadow Thief, and the Justice Society's longtime foe the Wizard are both in this grouping, as well as Copperhead, who had only appeared once before, back in the 60s, taking on Batman, Batgirl and Wonder Woman in Brave and the Bold. Thee narration mentions Catwoman as being there, but we never see her. Safe to say she came, didn't like what she saw, and left.
The villains then seem to be attacked by the Justice League, but these turn out to be easily defeatable robots. A warm up for the group, I guess. Manhunter then enters the room, acting as their leader, though mentioning someone mysterious being above him.
Manhunter gives a speech about how the group would be of benefit to them all, but also how the members will need to prove themselves. This leads to the final part of the story, a "test" run for Grodd and Copperhead.
It doesn't go so well. Copperhead gets shot, and Grodd leaves him behind. That's not it for Copperhead, though, and he will return a couple of issues down the road. On the other hand, this story is it for Shadow Thief. His absence in all later stories indicates to me that he was on the second, not shown, test run, and failed. Shadow Thief is next seen in Justice League of America the following year.
The fight with the robot Justice League was a definite improvement over the pilot story, and keeping Darkseid off page, just alluded to as the mysterious backer, is way more effective than using him as a robot. The larger line-up was also a smart move, making it easier to have villains fail and get caught, without disrupting the overall team.