I've begun work on a series of events relevent to Italy/The Western Empire. I'm familiar enough with modding that I can do most of this myself, but there are a few things that I can't do:
I'm terrible with graphics, so I couldn't get a flag and shield together myself (not to mention that i actually don't know what the flag should be).
Basically, what I have in mind so far is that, should a war between Italy and the Eastern Empire start over the Albanian region, it's possible for the Eastern Empire to win (as I have in my game). However, I don't really think it's plausible for direct annexation and occupation to lead to cores or anything, so I came up with the following;
An event where Sophocles (or whoever is Eastern Emperor at the time) approaches Vittorio with one of three options (depending upon what the Byzantine player/AI choses):
Vittorio is recognized by Constantinople as the patriarch of a new Western Dynasty and Italy is transformed into the Western Empire (with claims on Northwest Africa, the southern three provinces of Switzerland, Vichy France, and the East Coast of Iberia), with this option being the one Italy is most likely to accept as a surrender event, and the Western Empire is made a puppet of the Eastern.
Vittorio is again recognized as the patriarch of a new Western dynasty, but the Western Empire is incorporated into the Eastern with Vittorio as head of government and Sophocles as head of state. The claims from the previous remain and there is a minor dissent hit (to represent the Italians not being entirely comfortable with the new government situation). Byzantine gets cores on all of Italy's former territory. This one is the second most likely to be accepted by Italy (but much less than the first one). Byzantine gets claims on all of North Africa.
A direct annexation of of Italy by the Eastern Empire. Byzantine gets cores on Italy's territory, but takes a massive dissent hit for the fact that the Italians really do not like the new situation. This is the least likely to be accepted by Italy.
Through all these Mussolini is removed as a possible minister (because part of the flavor text will mention his execution as a prequisite for the surrender). Also, each one gives Italy the option of not surrendering at the expense of a large dissent hit.
Anyone who can help me with the flag situation can either send me a PM or post here. Hope you don't mind me doing some additional work on your mod, hammerfalls. It's a great mod and I enjoy playing it.
EDIT: Oh, and to clarify, the triggers for the situation involve Byzantine controlling Rome, Constantinople, and not being at war with the Soviet Union or Germany.