A Brief History of the Marque
Light motorcycles with Villiers engines produced by the Piana company of Firenze (Florence) from 1923 by Gualtiero Piana. In 1926, they released a new 250cc Villiers-powered model and in 1927 built a motorcycle with a 250cc single cylinder sidevalve engine, probably a JAP, which was selling the following year as the M 250 Standard.
The story begins much earlier with the brothers Ettore and Aristide Piana who succesfully competed in sidecar racing with a BAT V-twin-powered outfit.
Production ceased in 1930.
There is a website for the marque at motopiana.it
Sources: MC Storico Conti, Henshaw et al