I found the Bert Convy episode, which plugs his new movie Racquet, which per IMDB came out in June 1979. The one episode online with commercials appears to be from the USA rerun era. EOTVGS II says it aired in first run between January 1979 and February 1980, so I'll go with that.
Two tidbits:
- Too bad it's not on YouTube, but I do remember Elaine Joyce appearing on Make Me Laugh - and lasting less than five seconds into the first comic's act.
- It looks like most of the comics from the show were from The Comedy Store, or at least were Los Angeles-based. The spring of 1979 was a strange and awkward time for those comics - since there was a strike against The Comedy Store, who chose not to actually pay the comics. Long story, read William Knoedelseder's I'm Dying Up Here for the details.