 Complete the following phrase:  Although Bonetto had raced Formula One cars before, he made his World Championship F1 debut in the 1950 Swiss Grand Prix. He was five days short of his 47th birthday. He entered his own Maserati 4CLT in several Grands Prix, under the Scuderia Milano banner, and drove a works Alfa Romeo SpA in 1951, as their number three driver. He shared a third, with Giuseppe Farina in the 