There are so many minor appearances in the 80s (because of the Legion’s increased popularity and because Crisis) that I’ve decided to split the few ones from the 70s in a separate batch.
Superman #295 (1976)
by Elliot S. Maggin & Curt Swan
Superman is fighting Father Time this issue, leading him to a very different 30th century.
But this alternate future is prevented by a VERY convoluted plot involving Superman’s costume.
And speaking of convoluted: “Father Time” is actually this Green Lantern from the future, revealing that the Time Trapper used the power of the Green Lantern Corps to erase the Legion from existence!!!
The Time Trapper himself doesn’t even show up. Out of all the stories involving Time Trapper this must be among the most convoluted ones, WHICH IS SAYING SOMETHING.
DC Comics Presents #2 (1978)
by Martin Pasko & José Luis García-López
This is a team-up between Superman and Flash. Bizarrely enough, the concept of time being an endless cycle is a key plot point… while still mentioning the End Of Time.
So this is another rare instance of mentioning both things in the same story well before LSH vol.3 #50 (another instance being Action Comics #387).
Superman eventually gets sent to the 30th century, where meeting Superboy breaks the established rules since they shouldn’t be able to exist in the same period. Although there is a weird explanation for it.
The way to allow Superman to return home is to bang his head against Superboy really, really hard.
That’s not a joke, that’s actually how they solve this.
I don’t know what’s crazier, that the solution came to Superman in a dream or that IT WORKS.
And that’s about it.
Consider that, as explained in the Silver Age cameos, I’m not covering the times Mon-El appears on his own.
This one may or may not count: Weird War Tales #69 (1978) features a soldier haunted by a ghost from the future. The ghost is very obviously Colossal Boy. He doesn’t act like Gim, but the costume is unmistakable. Paul Levitz edited the story, so maybe the costume was a joke on his part.
More of an easter egg than a cameo but definitely worth mentioning!