Ben Wright, seen at the beginning and end as Di Cassals, played "Hey Boy" in the Radio "Have Gun Will Travel" with John Dehner playing Paladin.
Princess Serafina"s (Arlene Martel) country of Montenegro is a real country of about 5,300 square miles in the Balkans. In 1858 they defeated the Ottoman Turks and had their borders officially set. They gained their independence from the Ottoman Empire in 1878, which would have their political intrigue coincide with the era of Have Gun-Will Travel.
This is one of the few episodes in which Paladin does not perform a soliloquy during the opening credits foreshadowing the plot. He just points his gun at the audience in silence, then reholsters it.