This really is a sad story. Not so much about having two families as this was a common practice for these Italian men but the rest of it is truly a shame.
I tried to look up a few things online for you and wasn't too successful but I was able to locate some persons with the same surnames still living in Ventimiglia using the English translated version of the Italian White Pages
Click on the search icon to the left and then enter the surname and town. I believe you will get about 45 hits with that.
The address tot he Comune which you may find useful in the future is:
Comune di Ventimiglia
Piazza della Liberta 3
18039 Ventimiglia, Italy
telephone: 0184 2801
fax: 0184 352581
comune.ventimiglia @ legalmail.it
Hopefully this is a start and someone will come in and add to it.