Some Birth, Marriage and Death Records from 1592 of Church of Ireland, Methodist, Quaker and old Catholic Families, Skibbereen District, West Cork and Rochester, New York.
From around 1820 Catholic Records are generally available on irishgenealogy.ie. There was significant intermarriage in the 18th and 19th century and by looking up a ‘Protestant’ name on this site you come across intermarriage or neighbours acting as sponsors in baptisms or witnesses on marriage.
Protestant records suffered from being sent to Dublin Public Records Office for safe keeping and may were destroyed in 1922. Sometimes by accessing Canadian, US, Australia an British records it is possible to make up some of the gaps.
These records are a mere snapshot.
Courtesy Susan Beretta, Salt Lake City:
Local Loan Reproduction Records 1830s:
https://durrushistory.com/2012/09/02/schull/Tithe Aplotments 1820s:
Rochester,New York, there was mass emigration from the 1820s and many names in the greater Schull area (as well as Durrus) appear in church and other records of Rochester, new Yorkm in the 1820s a boom town now those days sadly past: