Where is the inner Italian border Timeline? I'm guessing that Sardinia and Sicily are in the free Italy, but the mainland border would be a major hotspot. A divided Rome could form the alt-Berlin of this timeline, and a Vatican city caught in the middle would make things interesting.
Rome was liberated by the Italian partisans during WW2 and became capital city of Socialist Italy. Vatican's neutrality is honored by the Soviet Union and its allies due to large number of Catholics in their countries. There is a map in the first post of a TL.