Yes, Leo the K. did use a Bozo (with the little thing over the z). It caused a big stir when he appeared with it in concert at NIU in '68 or '69. As did the Firesign Theatre. Ya see, all this stuff is connected.
This may be thread creep, but did anyone see the article about the Everley Bros. in Acoustic Guitar Magazine? They talk about Don's big Gibson on which he created all those memorable intros and revolutionized rock music. It really is a good article.