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 Mary Doolan M 1860 +/- 2 yrs somewhere in Ireland with the father's forename unknown, I found 8 rcds: 2-1858 Cork, 1859 Dublin, 1861 Kildare, 1861 Dublin, 1861 Limerick, 1861 Roscommon, and 1862 Roscommon.
For Robert Maslin M ditto, I found 0 rcds. Either their rcds haven't been transcribed, or they married in America.
For Mary Doolan B 1839 +/- 4 yrs, Co. Roscommon, with the father's forename unknown, I found 2 rcds: 1840 Roscommon parish and 1841 Knockcroghery. Father's forenames were Michael, and Patrick respectively.
For Robert Maslin B 1837 +/- 4 yrs somewhere in Ireland ditto, I found 0 rcds. This surname is extremely rare in Ireland. Note 3 may apply here.
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.