I believe that "Sunny Jim" was one of nine brothers.My great grandfather was his brother Charlie.Charlie was apparently the black sheep of the family.He kept going back and forth to County Derry in Ireland, e.g. my grandmother, Mary McNichol was born in Philadelphia.Her younger sister Elizabeth, was born in Derry.Eventually, Charlie was sent back to Ireland to take care of their mother, my great, great grandmother.The last contact we had was around 1926 when Charlie died and my grandmother got a letter from McNichols in Coolcosreaghan, a townland between Garvagh and Dungiven in Derry.They had taken care of him in his last years.
If you visit the Garvagh area, you'll find loads of McNichol people.In the cemetery near Coolcosreaghan, there are many McNichol graves.There are even some for people buried in Holy Cross Cemetery outside Phila. and other that just say "buried in Philadelphia, USA".
I don't know if this helps at all, but I believe we're talking the same McNichol line.