You'd be surprised about the amount of personal weapons around in early 1900 Italy. We're talking about pre-WW1. Gun ownership in Italy wasn't regulated until 1926 (Fascist Era) bar for a very specific set of weapons, in short concealed weapons (blades hidden in canes, smaller pistols, etc). Carry was theoretically under government supervision but no one really cared. In the South, no one truly cared.
So the standard Sicilian could be, and probably was, pretty well armed. Knives were standard, and revolvers or the ever-faithful shotguns common too. Naples had a long tradition of artisans making civilian firearms and the civilian market was pretty healthy. And let's not talk blades, Italians in the early 20th century had still people managing proper dueling schools and honor duels, up until Fascism.
Cars in the other hand are pretty much.... a difficult sell. After WW1, maybe. Before WW1? In Southern Italy?
The theme can be interesting, as the Mafia pretty much ruled the place before Fascism tried to fight it before bedding it.