I am starting to really get into the old Hammer horror films again like "Horror of Dracula" and the rest. I recently viewed "The House That Dripped Blood" on DVD and always thought it was a Hammer film. Turns out it was done by a competing British film distributor called Amicus. Seemingly, Amicus has a very similar history to Hammer and even hired many of the same actors and crew people to do their films, so confusion apparently is very common.
Amicus tended to do those "Tales From the Crypt"-type anthology horror films (as "Dripped Blood" is), while Hammer focused usually on a central character such as Dracula or Frankenstein or Kronos or something like that.
I hope that they see fit to release all of these films someday, especially films like "Twins of Evil" which I have never seen, but have heard a lot about. It is available on import in Region 2 and I may plop down some money for it as I have converted my DVD players to all region players.
Anyway, having fun with horror...