The images of the civil records and census are offline at the moment, but I'll check when they come back. Murphys can be very diffcult to follow as the surname is so common.
Have you found census records and/or marriage cert for Michael & Roseanna ?
I suspect the 'Briar Street' may be a reference to Sweet Briar Lane, which runs between Kilmacud Rd. Upper and Lower. Drummartin is also the name of a townland located immediatly to the west of Kilmacud.