As the cover of Superman 283 (Jan. 75) implies, Bates, Swan and Oskner give him a new secret identity in this issue.
Although we follow the life of Chris Delbert, the reason for this new identity is not made clear until the end of the story.
It turns out that Superman is being blackmailed by a prominent scientist, who has been monitoring him, and threatens to expose him identity unless Superman flies him to Mars.
Superman seems to go along with this, but apparently abandons him on the red planet. But then, it simply turns out to be a new amusement park. The scientist tries to expose the Delbart identity, but of course the man does not really exist.
More fun is the Mr. Mxyzptlk story, by Maggin, Swan and Oskner. It had been fully five years since we had seen them imp.
But now he is back, and causing chaos in Washington DC, as he brings the various statues there to life.
And though Superman does trick him into saying his name backwards, forcing him back to his dimension, he admits (to himself at least) that he missed “the little creep.” Good thing, as he would be back within the year.