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 county, 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 Mohill RC parish, Co. Leitrim, B/M/D rcds don't begin until 1836.
For James McLaughlin B after 1836, Mohill parish, Co. Leitrim, with a father forenamed Pat(rick), I found 2 rcds: 1842 and 1848.
For Bridget McLaughlin M after 1849, Mohill, Leitrim, I found 2 rcds: 1850 and 1855.
For ???? Purdy M ditto, I found 0 rcds for anydate in Co. Leitrim. Bridget and ???? may have married elsewhere. There are 36 male Purdy marriages 1850-1858 in the rest of Ireland in this database. Will leave it to you to try to match the two M rcds. This is tedious.
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.