The scenes that show the assassin having his face stretched and altered, was considered quite graphic for the times.
Sidney Blackmer plays a man who lost part of the third finger of his left hand in an accident. In 1940, Blackmer appeared in a comedy called Third Finger, Left Hand (1940).
This is the second instance where Phillip Pine's character's identity is usurped. The first being The Four of Us Are Dying (1960).