Tom in the Eircom Phone book There are just 5 Brien Families And one Rock
Not sure if this helps
O'Brien Charlie
Round Tower Castle St Roscommon
(090)6626252
O'Brien Elizabeth
Goff St Co. Roscommon
(090)6628611
O'Brien Thomas
12 Abbey st Roscommon
(090)6625005
O'Briens Health Foodstore
Lanesborough St Co. Roscommon
(090)6634174
Thomas O Brien
Roscommon Town Co. Roscommon
(090)6637656
Ballyfeeney Rock
Kilglass Strokestown Co. Roscommon
(071)9633222