You know, Amicus Films was responsible for another hidden gem called The City of the Dead (1960) also known as Horror Hotel. Today it has achieved classic status. It was distinguished in part by a highly unusual score -- unusual for Douglas Gamley -- that included Gregorian chants. The film is worth watching and the score is worth pursuing, especially if you like The House That Dripped Blood.
Horror Hotel is a wonderful film - John Llewellyn Moxey directed it. Very atmospheric and a wonderful Gamley score.