Hi Cousin!
My line is through their son, John, b.1766, who married Susannah Endersby in 1793.
Are you descended through Robert's daughter, Mary, by any chance? She married John Mansfield in 1831). More recently, this Mansfield line crosses through my in-laws tree, too.
Also, do you have a public tree on Ancestry? - I've one, but it's not complete by any stretch.
I'm keen to hear from you, either by pm or directly on this thread.
Regards. Carole