Okay, so I'm bringing out a dead horse to flog.... What are the ethnic backgrounds of the characters? Here's how I figure them...
Jerry is probably your standard Eastern European Jewish American. "The Cigar Store Indian" finally confirms this.
Elaine is possibly Catholic. First of all, she's giving out Christmas cards. Second of all, she worried about "the nip postcard" being sent to "Father -------." I figured she might be Polish.
George is Jewish, despite the Italian surname. There are two possibilities here: a) His father is Italian, his mother Jewish; he would get his last name from his father, his religion from his mother. b) His father is Jewish with at least one Italian male somewhere down the line. c) His parents are both Italian Jews. Considering the presence of "Kasha" in their house, the answer is more than likely b).
Kramer is the real mystery. I'm guessing he's a WASP, because to the other three, that would be the weirdest thing possible.
Dave