Ancestry Library has recently added two new Irish collections:
Ireland, Select Catholic Marriage Registers, 1775-1912 This collection includes Catholic marriage registers from 62 parishes in Ireland and coverage varies according to parish.
Ireland, Select Catholic Death and Burial Registers, 1767-1912 This collection includes Catholic death and burial registers from 19 parishes in Ireland and coverage varies according to parish.
The State Library of NSW has a subscription to Ancestry Library and you can use it free of charge in the Library. You may be able to use the tips from NSW State Records above to decipher some of the old parish registers.