I'm at a little loss in terms of my Leave It To Beaver expertise, since I never watched an episode of the show - so the cast in the pilot could have been Martians or they could have been the regular cast for all I know. ↗
My parents didn't want me to be a regular in a series. I was a working actor from time to time but they thought was a little too much being a star of a series. They wanted me to have a slightly more normal childhood. ↗
Teddy Wilson, I think, said a little while ago that it's much easier to come in and play whatever comes into your mind, without obeying any of the laws of bass line and harmony and so on. ↗