not so much a brand as an assembler. In fact, this factory was located in Fourchambault, France (in the Nièvre department), and assembled Piaggo-brand Vespas. A.C.M.A. stood for Ateliers de Construction de Motocycles et d'Automobiles, and operated from 1948 (although Vespa assembly didn't begin until 1951) until the end of 1962.
The ACMA brand

In short
Years of production
We do not yet have a motorcycle specifications for this brand. But the site
moto -collection
will probably have information that fits your needs.
Location
The history of the brand
Other brands
Here are other brands from
France, and having made motorcycles during the same period as ACMA