Sorry this is so late PJ, but I have been away from my computer all day.
My only source of information is the internet, and I have been unable to locate any information on cars designed by Michele Lanza other than the early ones produced by his own company, and the last one (from information found on AutoPuzzles). Nevertheless, based on your last post I think I have been able to narrow the engine possibilities down to three. The one I have settled on is from a car produced 24 years after Lanza's first car, was featured once on AutoPozzles, which has a small displacement, and which was produced in Torino (Lanza's base of operations).
Given the above, I'll say the puzzle car is: A torpedo (Vetturette?) by Michele Lanza using a two cylinder Temperino engine from about 1919.