Oh, this is just too much.
When Dean Martin decided to roast his good buddy, Don Rickles, he was given an extra half-hour for his Dean Martin Comedy Hour (formerly the Dean Martin Show). An extra special tweak was added when we were introduced to a man who supposedly was Don's primary writer. Despite the Hitler-esque mustache, there's no mistaking the voice of Casey Kasem, who never got to sit on the dais with Dean and his Hollywood buds, but was instead used as a special attraction. We've previously seen Casey as Telly Savalas' #1 fan (and dressed as Columbo, to boot), but let's turn the clock back to 1973. Casey shows up around the 18 minute mark.
Edit, 10/12/17: Unfortunately, the video has been deleted.
There is additional material on this copy, as the previous copy has been deleted.