GTA feature in Automobilismo D'Epoca
The Maggio-Guigno issue of Automobilismo D'Epoca has a giant feature article on the GTA, "40 anna in pole position"! I picked up a copy while in Italy last week. Unfortunately, I don't now of anyplace this is available in the USA.
Its a great article listing all the race results, chassis numbers, tech specs, etc. All in Italiano of course.