The 125 S used a steel tube-frame chassis[2] and had a double wishbone suspension with transverse leaf springs in front with a live axle in the rear.

Subsequently, the car was sold to its current owner, who refitted the chassis with a body similar to the factory's 125 S replica, which was built by Michelotto in 1987.

The car continues to be the subject of much debate among Ferrari historians and enthusiasts; recent developments indicate that the restamped serial number was in fact a correction and not an alteration.

The 125 S debuted at the Circuito di Piacenza, driven by Franco Cortese,[5] but was unable to finish the race, despite a favorable showing against the strong Maserati 6CS 1500s.

Two weeks later, the 125 S claimed Ferrari's first victory at the Grand Prix of Rome on the Terme di Caracalla Circuit, where it was also driven by Cortese.

The 125 S won six of its fourteen races in 1947, though drivers Clemente Biondetti and Giuseppe Navone were unable to win the 1947 Mille Miglia in it.