A Brief History of the Marque
Mario Acerboni (1889-1967) built light motorcycles under the M.A. and Acerboni labels during the interwar period.
Acerboni won the 1/3 di litro (350 class) Italian championship of 1911 riding a Frera machine. He was a member of the Frera racing team in 1929.
In the late 1920s he established a workshop and salesroom in via Pacinotti, Milano, selling Frera motorcycles, and also sold Panther, Coventry Eagle and New Imperial machines until the protectionist policies of the fascist government made this difficult - but not impossible. He and his son Gianfranco (also a good rider) imported the British machines in pieces and reassembled them.
When the Tradate firm closed in 1936 Acerboni bought up quantities of Frera engines which he used to construct lightweight three-wheelers and motorcycles. This may account for the fact that Frera machines appeared to be produced in 1937, after the company had closed.
Source: Moto di Lombardia