A sad comeback for a funny series. I saw it thirty years ago, and can remember very little of it except that Frank Faylen recreated his role as Herbert T. Gillis, though he was frail and rather hoarse yelling, "Dobie!"
I think, but am not sure, that Sheila James was in it as Zelda, but Florida Friebus (as Winnie, Dobie's mom) was noticeably absent. Maynard G. Krebs showed up late in the show, no longer a workaphobic beatnik, but now a zen-calmed hippie guru, which was about as funny as it sounds.
The follow-up TV-movie, "Bring Me the Head of Dobie Gillis", came along 11 years later and was a bit more successful at reviving the feel of the series, along with bringing back other TV cast members like Steve Franken and William Schallert.