The wheels are those of a Panhard Dyna and as they had a special brake-wheel construction I´m quite sure that the overall chassis is Panhard, too. But the bodywork is a one-off, I think.
Manufacturers like Sirio, Callista, Pichon-Parat, Drews, Wendler, Arista, Nardi etc. made bodies on the Dyna chassis, so it will not be too easy to find this particular one without any hint...