Here's Mel Blanc guesting with David Letterman…in 1982, I believe. You get the feeling Dave wasn't all that enthusiastic about having Mel on his show, perhaps because it's one of those auto-pilot interviews. Every talk show Mel went on, the host wound up asking him pretty much the same questions and getting pretty much the same responses. The audience seemed to be the right age to be excited about the voice of Bugs Bunny…but not old enough to care about Mel's days with Jack Benny.
Ignore the stats that Mel quotes about the costs of making an animated cartoon and the time it takes. (It may sometimes have taken up to nine months for a Warner Brothers cartoon to wind its way down the assembly line but no department worked on their part of it for more than about six weeks.) Also, the anecdote about Mel deciding to give Porky Pig a stutter after hanging out with live pigs is a tale Mel told in hundreds of interviews…but Mel was actually the second voice of the character. Porky stuttered because the writers wanted him to stutter and an actual stuttering comedian was the first voice.
Other than that, it's worth watching. It runs about ten minutes…