Herself is doing her own research, so I am not fully au fait with the story. She is also descended from James Brophy and Mary Mines (who, apparently, also came from Walkin Street) through their son John who lived at various addresses in Dublin, mostly between the Grand Canal and the Liffey.
John married in Dublin and his daughter, Mary Jane, married another stonecutter, and that is Herself's ancestral line.
By coincidence, Laurence was a near neighbour of my ancestors in Harold's Cross Cottages. I don't think Laurence actually lied about his age: in those days, people didn't really pay much attention to such things, and were fairly casual in making estimates (they become more careful, but not necessarily more truthful, when old age pensions were introduced in 1909).