How many movies have George Hilton and Stelvio Massi collaborated on?

They have worked on 6 movies together! Their first movie together was The Moment to Kill (1968) while their highest rated movie together was The Case of the Bloody Iris (1972). They have not worked together since Once Upon a Time in the West There Was a Man Called Invincible (1973). They are most known for their western films together.