Pietro Ghersi and a Maserati 6C 34. In the back, a truck for the "Scuderia Ferrari" team from Modena, they raced Alfa Romeos. One guess is that this is at XIII Gran Premio d'Italia at Monza on 8 September 1935, where he had entry #32 and raced for "Scuderia Subalpina".<a rel="nofollow" class="external autonumber" href="http://www.kolumbus.fi/leif.snellman/gp3509.htm">[1]</a> This reference says this was "Siena's car", i.e. Eugenio Siena, and that this team entered two "old" 6C35 with 3.7 litres. Oh, well.
Unknown photographer
<a rel="nofollow" class="external autonumber" href="https://www.facebook.com/photo/?fbid=2147497658913847">[2]</a>