It was built in 1947 by Romano Armellin. The aluminium for the bodywork came from a British aeroplane wing, and the steel tubes for the tubular frame came from four bar stools. 
Yes, that is how it's referred to on some sites, though others have differing descriptions! No two seem to say the same thing. Since the car currently resides in Germany I'll assume you know what you're talking about and give you the point!
It is referred to on the Autobelle site as a 1938 Fiat Topolino 500 Barchetta Vulumetrico, but my Italian isn't up to understanding that..
It's also described variously on other sites as 1939 and 1950...
A couple more pictures: