The father listed as J F is the son of the Darby I am missing. (He also shows up as J S Darby too)
Every record says that was a John S Darby, born 1710 in Ireland, but since the John F listed above was born in 1804, I don't think he was born when his father was 94? And his mother would have been in 30's? Her name was Susanna Welsh/Welch?
I have found a Susanna Welch marrying a John Derby, in 1793 in PA?
But thanks for helping, and hope you can find a way to go further back. I can't get past marriage records in PA church, and not sure those are the two I am looking for anyway.