Dr Haquenbusch, the plastic surgeon who changes Morzini's appearance, is certainly named after Dr Hugo Z Hackenbush, the horse doctor played by Groucho Marx in "A Day at the Races".
The character of Roger Morzini is a parody of Jacques Mesrine, the most wanted French gangster who was shot one year before the movie was released.
Michel Clément's mother (as Marthe Villalunga) is actually only 12 years older than him