Not really paying any attention at first, but I recognized a familiar voice, and there - in vivid black and white - was Johnny Carson, on a panel also including Tom Poston, Jayne Meadows (aka Mrs. Steve Allen), and Kitty Carlisle. Johnny looked very young, while Poston looked scarcely different from his Newhart role over three decades later.
My research indicated that the episode, sponsored by Anacin (helps drain all eight of your sinus cavities) and Sani-Flush, and announced by Johnny Olson (Bud Collyer hosting), was recorded in October 1961 - I probably wasn't even walking yet.
Carson of course went on to become the greatest late-night host of all time. Fortunate, as he was not so good at discerning the real Jo Thornton or Henry Gross.
Would Annie Lennox lie to you?