Sometimes you get lucky...
Found a source with more information today:
"Built on the basis of a Fiat 600 at the end of 1955. This car was discovered in a ‘barn find’ condition. It has various aspects which can be traced to the Canta coachbuilder like the dashboard-style Fiat 1100, and the rear fins that support the headlights also styled like a Fiat 1100, although there is no confirmation of this."