I search the IFHF's online database at ROOTSIRELAND.IE. It has abt 19 million B/M/D and other records for MOST Irish counties. Records before 1863 are increasingly sparse. By 1800, they are almost non-existant. Many B/M/D events either weren't recorded, or haven't survived.
For Hugh O'Brien B 1828 +/- 20 yrs, Co. Cavan, with a father forenamed P(atrick), I found 0 records.