I have distant Dineen- Buckley connection but looks like a generation before yours.
Mary Dineen sister of Dennis Dineen 1800 - ???? married an Owen Buckley of Knocknacopple.
Dennis was my gg grandfather who was son of Tadhg who married Mary Moynihan in the late 1700s. Taadhg was son of Cormac Dineen from the Bandon district.
Dennis had brother Charles who married Kit Murname or Warren and there was another sister who I'm trying to track who married a Ryan of Ballycullen.