Jeff Lindsey was born in 1947.
Bryan Furniss was born in 1970.
When Lou Grant invites Mrs. Pynchon to McKenna's, she remarks that she hadn't been there "since the night Mr. Truman beat Mr. Dewey." Harry S. Truman defeated Thomas Dewey in the presidential election of 1948. Since the episode originally aired in January 1980, it would mean that it had been around 32 years since Pynchon had gone to McKenna's.