This is both a rewarding yet sometimes frustrating avocation and a never-ending one at that!
The surnames we're interested in, for starters, are as follows:
Jean & Gagnon= Maine, Canada, France, etc.
Girardin & Duguay =< same >
Madri & Sarubbi= New York, Italy, etc.
Sgambati & Vetrano=< same >
For now, information from any time period would be appreciated!