I have only just seen your message so I hope it is not too late.
The RC parish records for Glinn start in 1817. If you want to go back further it might be worth looking at the adjoining parish of Wexford Town. The records are available on microfilm in the Library in Wexford Town of in the National Library in Dublin.
Sometimes the microfilm copies can be better than the original as parts can be easier to read and they should be complete i.e. no pages missing.
I would prefer to use the library in Wexford; it's smaller, friendlier, has better facilities and is cheaper for copies. In Wexford Library, you can book a two hour time slot on the machine. Ring them or if you go early in the day, you might get a slot for the same day. The machines are conected to a printer so you can get a copy of the record.