During this episode, Jonathan is wearing a blazer that includes the emblem of The William Holden Wildlife Foundation. This is the wildlife foundation Stefanie Powers founded after the death of her longtime partner and fellow conservationist, William Holden.
The horse Jennifer rides is called Prince Valiant. Robert Wagner played the title character in Prince Valiant (1954).
The car the Harts are driving is an Aston Martin V8 Volante, sometimes called the British Mustang. Today US examples of that model sell for over $250,000.