Was just thinking today (as I am wont to do sometimes) that the characters of Shlepperman and Kitzel can be interpreted as two different stages of Jewish assimilation in America.
Shlepperman is more the immigrant, self-consciously Jewish, trying to make his way in this country. He tries many vocations, opening nightclubs, tea rooms, restaurants, gas stations at the bottom of the ocean, and auditioning to be Jack's singer. His temporary West coast replacement, Patsy Flick, even speaks some Yiddish on the program.
Kitzel is still Yiddishkeit, but is in a higher state of assimilation. His son goes to a Catholic college, he says he's going to visit his relations in Ireland, he has a relative that everyone calls Tex (albeit because he's in the textile business). Kitzel's laughs often come from the juxtaposition of something very non-Jewish with his character. (Then again, Shlepperman did play Santa Claus on one episode.)
Kitzel's first appearance as a hot dog salesman is almost the exact same bit that was once done with Shlepperman's character, with the added call of "Peekle in the meedle mit de mustard on top..."
I'd be interested to hear other's thoughts on this.