In this episode we learn that George originally wanted to name his cleaning business Handy Dandy Cleaners and that it was Louise who suggested the name Jefferson Cleaners.
This episode ended with the deal falling through for George's first store, so it's conceivable that he didn't open that first store until a few years later, but 1974 would be too late, too (as another contributor pointed out regarding episode 92). It was established on the third episode of All In The Family that George opened his first store in 1971, after he won some money in an insurance settlement from a car accident.
This episode indicates that George opened his cleaning business in 1968. However, back in Episode 92, the show flash-forwarded to 1996 where they were celebrating the 22nd anniversary of George's business (implying that it had opened in 1974).
Taped on February 12, 1980.
In Episode 4, Lionel the Playboy, Louise mentions that Lionel is 22, that's 1975, then he would be 15 in 1968, and Lionel was a full grown teenager in this episode.
Roxie Roker, Franklin Cover, Marla Gibbs, Berlinda Tolbert, and Paul Benedict do not appear in this episode