Two points for Iluvatar!
The coachbuilder is indeed Scioneri (which was a former employee of Fissore and who took over the military production of Viberti when his plant was destroyed by the British bombing).
And cars 3-5 are Fiat 1100/103.
For Bill: he was also reworking ex-army vehicles. Not only them, however.
And the cars are 1100/103 with unibody (see the wheelarches) and not former versions with separate chassis.