I know this thread is old but I stumbled across it and hope you "Glocky" see this.
I am the grandson of your father's brother - Danny, your dad being known as Uncle Fonsy?
The grave you describe at Aughaclay is that of your grandparents, the gravestone (with picture) was put there by my dad (Terry who died in 2015). The family nickname was Billy - hence the grave inscription - we were the Billy's.
I have been over a few times myself and there were a few distant relatives over there then - I think the grave was tended by a man named Seamus Harkin, who had a garage in Gleneely and whose mother may have been a sister of Lizzie - your grandma.
Hopefully you will see this and get in touch - I can probably help you with some questions!