Not much publicity given in this double-bill pressbook for The Human Duplicators. The poster imagery is attention-getting, but that's about it. My guess is that's where most of this movie's budget went.
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I don’t believe Lon Chaney’s Phantom of the Opera appears in The Human Duplicators, but this card makes effective use of his horrific face. Richard Kiel (Jaws) also stands out as the monstrous villain holding one victim’s head while dangling another barely dressed victim from his massive arm. Surprisingly, this illustration is taken directly from the American poster, and is not a figment of some underpaid, but highly creative, Mexican artist’s mind (just an American one).