Giovanni has been Americanized to
John (even Gio); I've never seen a
Giovanni called
Joe.
You might be better off on the board that discusses this sort of topic, where there are other authors -- I think it's the "name opinions" board. You can also search genaeology sites or Italian-American history, or look at Italian history from the time period you're writing about.
Interestingly Italian names of that generation are coming back. I see in my own family that people Americanized their son's names around the period you're talking about, and now their sons are naming their own children the names of their grandparents' original names. Lorenzo-->Lawrence--->back to
Lorenzo. Carlo--->Carl---->back to
Carlo. I think some current Italian names, therefore, might give you an answer.
Felice is a good one, because in
America it's a female name (fuh-LEES) though in Italian (feh-LI-CHAY) it's male and was changed to
Felix or something more "Americanly" masculine out of the "immigrant embarrassment" or "wanting to integrate" feelings of that time it seems you're going for.