Elliot S. Maggin's first Superman novel, The Last Son Of Krypton, begins with Jor-El whereas his second, Miracle Monday, begins with Jonathan Kent. Clark Kent's story begins in Smallville, not on Krypton.
Maggin writes the Silver Age/Earth 1 Superman:
Clark was Superboy before he became Superman;
the Kents sold the farm and ran a shop;
Superboy had a secret tunnel;
the Kents died before Clark became Superman;
Luthor was a much imprisoned, much escaped criminal;
Kent moved from the Planet to TV;
he was hassled by news reporter, Steve Lombard;
this is the most powerful version of Superman;
no doubt there are many other differences from more recent continuities.