I had a chance to conduct a follow-up interview with Joe Hale a few days ago and his wife sent me the following photos of Wilfred Jackson with the following explaination:
[Joe Hale: I worked on Wonderful World of Color for about ten years starting with Wilfred Jackson and Dick Huemer. The episode that I remember the most was the TV version of "Toot, Whistle, Plunk, and Boom."
This was my first experience with shooting Walt's lead-ins, and also my first experience in combining Animation with Live Action. Walt was working with Professor Owl. I made a cutout of Professor Owl and used it to show Walt the size of the Owl. It is very important for the actor to make eye contact with the cartoon character.]