Black Dragons (1942)
https://www.youtube.com/watch?v=gXJamhA22S4 - from the Cult Cinema Classics YouTube channel (1 hour 1 min long - 720p)
Synopsis:
It is prior to the American entry into World War II, and Japan’s fiendish Black Dragon Society is hatching an evil plot with the Nazis. They instruct a brilliant scientist, Dr. Melcher, to travel to Japan on a secret mission. There he operates on six Japanese conspirators, transforming them to resemble six American leaders.
Directed by William Nigh.
Cast: Bela Lugosi & Joan Barclay.
Trivia:
The film was rushed into production following the attack on Pearl Harbor. The original working title was ‘The Yellow Menace’.