We received an e-mail from Amanda Bellamy. She is the great-granddaughter of Augustus St. Clair Pask who is the great-grandson of the Monmouthshire progenitor Isaac PASK.
Amanda has provided the maiden name of Augustus' wife. She was Elizabeth COUSINS. They had a daughter Eunice JONES (Amanda's grandmother), one of four children who lived in Ynysbwl in South Wales.
Further research will be required, and an update posted in the near future.