There is a really great story in Action 336 (April 1966), but it’s not the one on the cover.
Superman is the titular star of this story by Hamilton, Swan, and Klein, but the real star is Ak-Var.
As a youth, back on Krypton, Ak-Var had stolen the sun-stone as a prank. But he was captured, and sentenced to thirty years in the Phantom Zone. In the intervening time, Krypton exploded. Superman comes to Kandor as Ak-Var is released, having completed his sentence. Phantom Zone regulars Jax-Ur, General Zod, Kru-El and Professor Vakox all cameo.
Ak-Var wants to stay on Earth, and use his powers, just like Superman. But the rules are that anyone released from the Zone must take up residence in Kandor – although the Kandorians are none too pleased to have him around. In fact, the story almost seems to imply that Ak-Var is one of the only people ever released. He does run into his old gang, and his former girlfriend, all of whom have aged, while he stayed ageless in the Zone.
This story gives a lot of detail about life in Kandor. Van-Zee, the double of Superman, takes a liking to Ak-Var, and introduces him to his niece, Thara.
Ak-Var former gang friends launch a crime spree, and frame Ak-Var. Being only recently released from the Zone, no one believes him innocent, except Superman, Van-Zee and Thara.
Together, they expose the gang members as the real criminals. Ak-Var becomes Van-Zee’s lab assistant.
Van-Zee is not seen again for a decade, returning for a story in World’s Finest Comics. Ak-Var and Thara have to wait even longer, coming back in the Nightwing and Flamebird series in Superman Family in the late 70s.
Supergirl comes back to Earth with her transformed face in the concluding half of this Binder and Mooney story. Superman tries to help restore her features, but with no success. Comet doesn’t care about her looks (he’s a horse after all), but notices her way of thinking has changed, and doesn’t like that.
She feels like a freak, and takes off for Bizarro World, thinking to fit in there. Wanting to fit in on Bizarro World is a pretty dumb idea.
Linda is stuck wearing a mask over her real face, but discovers that , somehow, her original appearance returned. She learns that the man who caused it was so grief stricken by his actions, that he changed her back. And so she ends, happily dancing with Dick Malverne.
An easy out.