In "The Crow's Nest," Long John Silver and the newly freed slave, Abed, are talking. Long John tells Abed about his wife who was a black woman. This comes straight from the original Robert Louis Stevenson novel where it is mentioned that Long John Silver's wife managed the Spyglass Inn and was a "woman of color."
Most of the cast have appeared in Doctor Who (1963).
Bruce Purchase played the half-robotic space pirate The Captain in Doctor Who: The Pirate Planet: Part One (1978).