Continuity mistake: After the Jackal has boarded the train to Paris, we see two subsequent shots of a different train.
Other mistake: When the Jackal shows his papers to the policeman to gain access to the apartment he will shoot from, his identity card gives his date of birth as July 1910. The events in the movie took place in 1963, which would make him just turned 53 years old. Yet his disguise suggests he is trying to give the appearance of someone much older than that.
Continuity mistake: The Jackal is driving a car with the registration GE 16 17 41 when he crosses the border into France from Italy. When Level later receives notification that the Jackal has crossed the border, he recites the registration to Caron but tells him it is GE 17 41.
Answer: Chins have sebaceous glands (natural oils). He rubs the key on his chin to lightly coat the metal key as a lubricant, so it does not stick to the mould. It will make a perfect impression in the mould to create a flawless cast.
Super Grover ★