The fine announcer and comedy historian Christopher Bay writes to tell me where that Allan Sherman clip is from. Sez he, it's from 1966…from the syndicated variety series, Something Special, which he says he watched on Channel Nine here in Los Angeles. Now that he mentions it, I vaguely recall watching it on that show on Channel Nine here in Los Angeles, too. Thanks, Christopher.
And while we're at it, everyone who reads this site except Christopher Bay wrote to tell me the origin of that Mel Brooks clip from the other day. It's from the British chat show hosted by Gloria Hunniford.