A BBC documentary from 1987 tracing the history of Britan’s famous Hammer studio. Interestingly, the title implies that the BBC was not immune from the common confusion between Hammer and Amicus; The House That Dripped Bood was an Amicus production.
NB: This material has never, to my knowledge, been commercially available and no copyright infringement is intended. It will be removed on request. I uploaded it for its educational and historical value.