I pop in the 1st DVD of Seasons 1 & 2 and watch the very first real pilot, The Seinfeld Chronicles (now note the DVD has it twice: "original" and "revised" versions) and I notice the following noteworthy nuggets:
*The coffeeshop is not the same and it's a table, not a booth
*The outside shot of Jerry's apartment building: it's not the same apartment building as later on
*The first "trashing" of George is the waitress making sarcastic remarks (like how nobody wants to see him on caffeine)
*The very first act of deceit is the coffeeshop waitress declaring serving regular coffee to George (or so she says) against George's wish
*The first entry of Kramer into Jerry's apartment: HE KNOCKS ON THE DOOR and does not just barge in
*There is clear and unmistakeable reference to how George should be doing the opposite (I can't recall the exact transcript but it can't be missed if you had seen The Opposite recently)