I find it curious that this have seemingly been worked on for decades and that the book was published years before the recent hearings that brought up the incident again. It could either support the claim as an independent third party, but could as easily be the source of the claims as well.
I did some quick digging and found an article I shared with the community (UFO Contacts in Italy Volume Two).
It talks about “Velivoli Non Convenzionali” or VNC as an acronym for “Unconventional Flying Vehicles” and a VNC sighting in Venice, 1931. That could be it.