A Brief History of the Italian Marques
Manufactured by Società Automobili e Motori, Via Boccaccio N. 9, Legnano, 1922-1928
Their first model was a three-wheeler named the S.A.M. Vaghi, powered by an 1100cc engine. Also available as a four-wheeler, the marque entered the field with to great aplomb, taking the first three places of the 1923 Milan Cyclecar GP. 1
The Vaghi was originally built in 1920 by Motovetturette Vaghi SA.
Subsequently they built only four-wheeled vehicles.
Notes: 1. autopassion18.com says they took 3rd, 4th and 5th.
Sources: Period literature, wikipedia.it
Ditta Ludovico Boltri di Mezzi, Ganna Cia. of Milan began producing Vaghi cyclecars in 1920, two of which were sold in England. The company name was changed to Motovetturette Vaghi SA, and was later sold to Società Automobili e Motori (SAM) who continued production of the SAM Vaghi.
Shown at the Esposizione Motociclistica di Milano of 1920, the Vaghi tricycles were designed by Guglielmo Ghiodi and were powered by V-twin engines of 970cc, and 564cc and 1099cc engines were also employed. It is possible that one of these was a flat twin.
Sources: wikipedia.it, wikipedia.de, aisastoryauto.it.