Count Giannino Marzotto thought Ferraris too heavy and too slow, so he made his own, using Ferrari chassis and powertrain and radical notions of improving aerodynamics.

he started with a Ferrari 212 Export Berlinetta engine mounted on a 166 Touring Barchetta. At least, that is what the translated text seems to say at http://www.elenaferrari.net/uovo.html

http://slotadictos.mforos.com/966558/11399961-la-mille-miglia-segun-carrera/
http://www.elenaferrari.net/uovo.html
http://propublica.com/UnZip/www/Mythos/6.html