Beverly Hillbillies, The Easter Egg - Who Is Buddy Ebsen?

In the episode where the bank is putting on a talent show, Granny and Jed watch Mr Drysdale and Miss Jane pratice a soft shoe routine. Granny turns to Jed and says "They're good, but they're no Vilma and Buddy Ebsen" and Jed pauses a moment and then says "Who?"
Of course Jed was played by Buddy Ebsen, who started his show biz career in vaudeville with a song and dance act with his sister Vilma.