So when Superman ask them how they have the same powers as himself, U-Ban replies:
"Super-powers? How amusing! Where I come from, everyone has see-through vision, extra-strength, and extra-speed!"
So I had to keep that bit of info out since that origin was re-conned during the Sliver Age.
I think you should have kept the facts as they were written in the story, because those are the events that happened at the time. Here's an example of how Fleisher handles such things, this one taken from the massive Superman entry:
According to the earliest accounts, Clark Kent embarked on his super-heroic career as Superman only after reaching adulthood, and first learned of his extraterrestrial origins as late as November 1949.
In the years that followed, however, these early accounts underwent substantial revision. In the newer version, Superman was portrayed as having battled crime and injustice as a youngster - as Superboy - prior to embarking on his adult crime-fighting career as Superman, and he was described as having learned of his extraterrestrial origins while still a boy by overtaking and photographing light rays that had left Krypton before it exploded. In addition, it was stated that "Because of his super-memory, Superman can recall all the incidents of his childhood!"
Despite this revision, however, all the texts of the Superman chronicles agree that Superman has lived a double life since the onset of his super-heroic career, using his super-powers openly only as Superboy or Superman while concealing his true, extraterrestrial identity beneath the deceptive guise of mild-mannered Clark Kent.