I can distinctly remember in the great old days of the Merv Griffin/Mike Douglas 1970's talk shows, a guest shot on Merv with Audrey Meadows. She told a great story about the production of these shows. When Jackie Gleason, in character as Ralph Kramden, would angrily, and with an exasperated expression on his face, pace up and down the stage while saying nothing (a funny "character bit" that Ralph often did when he was arguing with Alice or Norton, as though he couldn't...even) it actually meant that he had forgotten his line and Art Carney and Audrey knew that meant they had to launch in to steer the scene back on track. It never failed and they knew exactly what they had to do when they saw that look in his eye. An amazing production.Now that you mention it, I do recall reading (quite recently, in fact!) that no subsequent retakes, or even pick up shots were done! The cast and crew had to rely on getting the production sorted out during rehearsals. Given the spectacular results, this was a truly remarkable collective achievement!