A Brief History of the Marque
The first Italian post-war scooter, the machine was built from 1949 to 1953 by San Cristoforo of Milan using a two-stroke engine of 98cc in a tubular frame. Initially built by Gianca of Monza, the Nibbio - meaning "Kite" in English - was designed by Scarpa, who also designed the Iso scooter.
In 1949 manufacture passed to San Cristoforo who developed a new two-stroke 125cc engine with disc valves.
In 1952, a restyled version was announced as the Simonetta.
Sources: MC Storico Conti, moto-collection.org, et al.