Francis P Featherstone b. about 1810 orphaned children

I have reached a block.I have cencus and birth records for a Darby Featherstone who settled in Bothwell, Zone Co. Ontario.According to Darby's Grandson, my grandfather, Darby's father was a Francis P Featherstone who died before boarding a ship to North America. (possibly on a ship called the Mayfair)His wife and six children, one of whom was Darby, continued.His wife died on the journey.The oral history was confirmed when my uncle went to a family reunion of the Featherstone Family in Ontario.They supposedly have a pic of a gravestone of Francis P in Roscommon Ireland.

According to the cencus record Darby and his brother Hugh, also of Bothwell, Zone County Ont.were born in Ireland.I would like any info on Francis, any info a boat called the Mayfair in the mid 1800's or any birth records of Darbyb. 1830 Hugh b. 1837.The six siblings were farmed out to families and it appears only Darby and Hugh knew each other after the separation.Anyone else know anything of this family?

Where do I start.I know none of this is conclusive but if I can find the birth records of Darby in Ont. or his brother,