Yes, that was the Grand Prix where he supposedly had a copy of the Italian national anthem on him, as a good luck charm or so the story goes.
The February issue of
Motorsport Magazine has a wonderful piece on Nuvolari. I read it in the afternoon, which made me feel really nostalgic about many things, and ultimately led me to post that video.
And there's a lot of footage of him on youtube and general info on the web. All you have to do is search.
Nuvolari was really talented, but you must take into consideration that back then cars were horribly unreliable and unequalized, despite the 'attempt' at regulating them. "Luck" had a huge role in success or failure. Although in this case he was undoubtedly regarded as the best of his era, even by Achilles Varzi.