Due to Mary Tyler Moore having a flare-up of her diabetes, during a good portion of filming this season of The Mary Tyler Moore Show (1970), During the times Ms Moore wasn't feeling terrific, efforts were made to make her workload easier; one way was to lessen the amount of time she needed to be in makeup and hair, by having her wear a wig. Although this was kept quiet, the wig she wore (as seen in this episode), wasn't very close to Mary's usual hair style; a variation on a simple, side-parted hair style. Her eyes were also extremely sensitive at this time, and in several episodes, Ms Moore couldn't wear the false eyelashes (most actresses wear).
Beverly Garland wore a wig, just in case Lou's parting gesture didn't work on the first take. Fortunately, Ed Asner got the gesture right in one attempt.
While the relationship here was said to have taken place about 30 years earlier, they last saw each other 17 years earlier, in An Eye for an Eye (1958) (an early forerunner to Police Woman (1974), in which Beverly Garland had starred as a female NYPD police officer, who'd work undercover).