The quality is a little rough, but you see a mutual affection and comfort in clips like this vintage Good Morning America clip from our Hart playlist:
To me, this clip is a classic example of their chemistry even though the two are promoting another property. This is from 1983's James Bond: The First 21 Years, a special that appeared on ITV and showcased the likes of then-Prez Ronald Reagan! ABC in 1983 was the network home of the 007 films and of course of Hart to Hart. It's one of my favorite types of celebrity clips: When performers are in character despite appearing as themselves.