I research the Irish Family History Foundation's database. It contains 12,000,000 surviving rcds for abt 65% of Irish counties. Rcds are increasingly sparse B4 1840, rare B4 1800.
Note 1 - Without a KNOWN parish, the chance of an ancestor's rcds NOT being in this database is AT LEAST 35%.
Note 2 - Only 1/2 of Co. Cork's rcds are in this database.
Note 3 - The RC church kept control over most parish rcds from Tipperary (north). These are ONLY available thru the Tipperary Family History Research center at a substantial fee (regardless of outcome).
For Mary Curran B 1824 in Co. Louth with a father forenamed Peter, I found 1 rcd in Termonfeckin parish.
For Mary Curran M 1843 +/- 2 yrs in Co. Louth, I found 3 rcds: 1844 Termonfeckin parish, 1845 Ardee, and 1845 Monasterboice.
For Pat(rick) Moyles B 1819 in Co. Louth with the father's forename unknown, I found 0 rcds. In 1819 only abt 55% of Louth's parishes were keeping B rcds. Also, while the sources may show rcds begin in a specific yr, it doesn't mean that all events were rcd'd.
For Pat(rick) Moyles M 1843 +/- 3 yrs in Co. Louth, I found 0 rcds. It is unlikely, but not unheard of, for the bride's M rcd to exist without the groom's, and vice versa.
I didn't find potential siblings for Mary in Termonfeckin parish. There are other Currans with fathers' forenamed Peter in the 1820-1850 era in Co. Louth at large.
Google the Foundation's name to lead you to this database. Register, opt to be notified as rcds are added and browse. Pls post your search results to my genforum msg.