In real life, one of Jerry Seinfeld's first TV appearance was on The Merv Griffin Show in 1981. Seinfeld was just 27 years old.
The "commercial break" music Kramer (Michael Richards) chose for his Merv Griffin set is the same as the theme music of the "Jerry" sitcom pilot from episode 4.23, The Pilot (1993).
Jerry Seinfeld actually appeared on The Merv Griffin Show (1962) in 1986 (Episode dated January 4th).
The scene where Jerry and Kramer talk about Cain and Abel in the beginning was cut in syndication.
When Kramer (Michael Richards) plays his pre-recorded theme music as George (Jason Alexander) enters, a voice says, "Turn music off." This joke was previously used in episode 8.21 The Muffin Tops (1997), when a similar instruction was recorded on the tape of banjo music Kramer used for his "Peterman Reality Tour."