I came across this posting in regards to the Sgambelluri's. Your friend’s father is most likely, my great grandfather’s younger brother. “Raffaele Francesco Sgambelluri” who was born on February 2nd 1186 in Siderno Italy, is listed as the 5th child born to a family of 6. Of the children it was only him and my great grandfather who immigrated to the US in the late 1800’s.
Unfortunately it would be hard to locate any information regarding where he went and why he did not return to your friend when he was young. If he were to leave to be with family his only two options at that time would have been back to Italy or to Guam with my great grandfather. As of now I have not heard of an immediate family member joining my great grandfather on Guam, but I could always check with my mom.
In my family there is only one remaining connection to that period in time. She is my Aunt who would most likely be your friends first cousin. She now lives in California with her family.