John Both St. Mary's are on the Meath side of the town, actually within a few hundred yards of each other. The National library in Kildare St in Dublin have the microfilms for St. Mary's RC for BDM. There are genealogists in the library that will help you on site to locate the records you need there. St. Mary's microfilm is illegible in places but does go back further than 1864 to the mid 1700's approx. Enjoy your visit.