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 Marg(aret) McCluskey B 1840, Co. Fermanagh, with the father's forename unknown, I found 0 rcds. Only 10 of 22 RC parishes in Fermanagh were keeping B rcds as of 1830.
For Pat(rick) McManus B 1840 +/- 4 yrs somewhere in Ireland with the father's forename unknown, I found 104 rcds, with 32 in Co. Fermanagh. This is too many to easily summarize here.
For Ann(e) Faherty B 1873-1887, Co. Mayo with the father's forename unknown, I found 2 rcds: 1884 Louisburgh district, and 1885 Clare Island RC parish. The father's forenames were both Pat(rick).
For Win(ifred) LaVelle M ????, Co. Mayo, I found 7 rcds: 2-1864, 1868, 2-1870, and 2-1876. The parish/districts for the 1876 rcds were Louisburgh, and Clare Island
For Pat(rick) Faherty M ditto, I found 4 rcds: 1866, 1872, and 2-1876. The parish/districts for the 1876 rcds were Louisburgh, and Clare Island.
The rcds for Ann, Winifred and Patrick are likely for your ancestors. A view of the detailed rcds is likely to show the correct parents and marriage couple respectively. If so, the view SHOULD also show the bride and groom's parents' names as well as other info.
For Winifred LaVelle B ????, Co. Mayo with the father's forenames unknown, the earliest rcd I found was for 1875. This is too late for your timeline.
For Pat(rick) Faherty B 1851 +/- 4 yrs ditto, I found 0 rcds.
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.