Lucille Ball has Norma apply cold cream to her face before wiping off her lipstick and eye-make-up, rather than be seen on camera without any make-up.
While Malcolm's dental school diploma on his office wall does bear his character name, it is obviously taped over another name.
As the Waiter, Sid Gould wears the exact same gold jacket he wore so many times playing waiters on "Here's Lucy."