I'd like a big chart too.
The Fausti is the same as the Izzy Rizzini (F.A.I.R.) which they did buy.

I THINK Sabatti makes the O/U frames and possibly the barrels for all of them; Rizzini B, CG, Fausti, and others. How else can they be so identical? And it fits into the old manufacturing model that is so successful for the gunmakers in Italy.

I did take a very very close look at the in-the-white Sabatti O/U set Galazan's is selling. It's indistinguishable from the sideplated CGs and Rizz B's. I wish I'd brought a dial caliper, next time up there I'll try to remember.