The village set is the same one used in the original Frankenstein movies.
The jail cell used in this episode was also used in an episode of Star Trek season 3 (all our yesterdays) and in Battlestar Galactica 1978 season 1 (the long patrol).
Buck Rogers wears a hat as part of a disguise. It's the only time anyone ever wears a hat in the series. Ironically, he later tells everyone on the Searcher ,"hold on to your hats".
The hag tells Alfie they will be "living high on the hog". While humans have been eating pork for thousands of years, the phrase "high on the hog" was first used in the late 1800s and in the U.S.A. It means to live an affluent life style. Arguably the phrase originated from rich folks eating expensive pork chops and loin roasts (from the top part of the hog) while poor folks ate cheap hog's feet and ankles.
Relcos while imprisoned in the cage is supposed to be a golden man , his left palm has failed to have the have the golden treatment and can be clearly seen as an unpainted hand.