No he had done that a few years before I think but Johnny liked it so much he was happy to have him as a guest anytime. I looked up Jimmy on IMDB and at that point he was pretty much retired from acting. His final credit is a voice for the animated movie An American Tail Feival goes West in 1991. Jimmy left us in 1997. He did a mini series in 1986 (North and South) A tv movie in 1983 and 2 others in 1980. So he did 4 acting gigs in the 1980s but he started showing up on Carson because I think Johnny saw a lot of the American everyman in Jimmy which I think Carson was also but in a very different way.
Interesting..thanks..note Post #34—hope you were able to see the show.