For the greater part of the '80s, Harrison interviews were rare. Lucas would be seen
here & there on TV at the time but Spielberg was probably the most media-friendly.
Usually, though, when any of them were seen talking about Indy, the interview was
on set/location or part of a documentary. Personally, I don't remember any "talk show"
appearances but, hey, I was in high school and daytime TV was not something that
I paid attention to.
1981 also saw the beginning of "Entertainment Tonight" which was the place to catch
any Indy news/interviews. I was lucky enough to record K.Capshaw in '84 plus two
other choice interviews from 1989. (A.Doody & J.Rhys-Davis).
The 1st late-night show I saw with Harrison Ford was around '90/'91 promoting
either "Presumed Innocent" or "Regarding Henry". I taped it and have not watched
it since then. The 1st time I saw G.Lucas on late-night TV was last year on
"The Stephen Colbert Report" (I'm sure there are other appearances that
I'm unaware of).