Wow - gotta love English Records! DO you have an actually copy of Francesco's death? There are a few very good sites which provide free access to Italian Civil records from Northern Italy. Unfortunately since he was born before civil records you would probably need to search Church records or Catasti (land tax census) but without a town that isn't going to be easy. Have you been able to obtain Naturalization records for him? Maybe they will list where he was born? On
castlecarden.org there are some people with the surname that went to the USA - Maybe that will offer some clues for you.
Last name First name Age Sex Arrival Date Place of last residence
CODONI AUGUSTE 15 M 6 Dec 1877 U
CODONI MARIA 58 F 30 Sep 1900 CORIPPO
CODONI FRANCESCO 35 F 30 May 1892 MOBERLY MO
CODONI GUISEPPE 18 M 25 Nov 1885 U
CODONI MARIA 58 F 30 Sep 1900 CORIPPO
CODONIS LEONIDAS 20 M 11 Mar 1904 PATRAS