I'd like to start with this:
La Sport e i suoi Artigiani 1937-1965 by Andrea Curami and Piero Vergnano
In this book you can find all the etceterini, from the famous ones till the very obscure ones.
In the 1st part of the book there are 50 pages with all the results of the Italian Championship in the Sport cathegory (Mille Miglia, Giro di Sicilia, Targa Florio, ....) sorted year by year and more than 100 pictures.
The 2nd part is dedicated to all the cars that raced those years, you can read in the index, there are all of them! For each firm there is a long article plus a picture of almost the complete production and all the variations of the cars.
The 3rd part is a 10-page story of all the Sports with pieces coming from the ARAR camps, usually on Fiat chassis but equipped with BMW R75 (for the 750 Sport Internazionale cat.) or Zundapp KS750. There are 35 pictures of these custom cars, for some of them, the author gives Pilot's name and coachbuilder, for others, it is unknown if the pilot is also the builder.
The last part is a list of 90 pictures of cars, and for each car the author reports few data: year, race, pilots and car, when these info are available.
