I was going to write an article about, but hey, you really want these info!
Testadoro was the commercial name for a special head for the Fiat 500 A, distributed by G.R. Casa dell'Auto srl in Torino, and Giorgio Giusti was the owner. This was a project of the engineer Arnaldo Roselli (involved in the Volpini cars and the "R" in G.R.) and the name (testa d'oro = golden head) was due to the bronze color of it. It was made of bronze because, even if more expensive, that material had better qualities. There were 3 versions of this head, N,S and C, with an increasing diameter of the valves and compression ratio. To increase his business Giusti realized a Sport car, called Drin-Drin after his wife's nickname Andreina. This car (the one of this puzzle) had a modified Fiat 500A chassis and the engine was raised to 660cc, the top of the category in his class. The head was of course a Testadoro Tipo C (corsa). This car raced in Montlhery and other minor races in 1947 with success. It received a new body by Zagato soon after(pic.#3-4-5). In 1948 was ready the Marinella, named after Giusti's daughter. This car was a totally new project, with a Gilco's chassis and an original engine, with 742cc and an alloy head. It was built in a cigar-body by Zagato (pic.#9 with Elio's signature) and it race successfully in 1948 in the Michelin's cup, in the Valentino's circuit and, in a new Barchetta-body by Zagato (pic.#8), in the Giro di sicilia and Mille Miglia in 1949. In 1949 was ready the Daniela (pic.#6-7), named after Giusti's 2nd daughter, with the Marinella's engine raised to 48cv. Once again it had a Gilco's chassis and an Alfa Romeo 158 lookalike body by Zagato. With the death of Roselli in a car accident in that year, Giusti left the races. The Testadoro Specials kept on racing in private hands and in 1952 Dario Dal Monte Casoni took a Daniela with a Testadoro engine equipped with a Siata type B head and called it the Acme Special (pic.#10 in the bottom-left corner). Mauro Vinattieri in 1952 raced with a Testarossa (!) Special (pic.#10 in the bottom-right corner), actually a Daniela equipped with a Giannini G1 engine. Angelo Poggio raced with a Siata-engined Testadoro (last picture) in the 1952's Coppa della Consuma.
In 1947, Gino Valenzano ordered a "Sport Internazionale" racing car for the 1100's class to Count M. Revelli di Beaumont and Augusto Monaco and this car was built in Turin and equipped with a Testadoro head. The body was (of course) designed by Mr Revelli but wasn't successful.
