I finally remembered to make a video, showing you both versions of this episode.
For those of you who don't know, let me copy and paste my YouTube description:
John Randolph was the original actor for Frank Costanza, but ended up being replaced with Jerry Stiller after just 1 episode. Therefore, the scenes with John Randolph was re-shot with Jerry Stiller, and was used for the syndicated version after the original airings of Seinfeld.
What I didn't learn until today, by looking at the Season 4 "behind the scenes" footage that's available on the DVDs, is that it was Larry David's decision to re-shoot these scenes. And they didn't The Stakeout, in Season 1, where Jerry has a different father, because by the time Larry got the idea to do so, 4 years had passsed and he thought it would look weird (which it would.)