Jack:
The RC church for Magorban civil parish would be Killenaule. Records for this church go back to the 1700s with one gap period. Here is the link to the parish register which goes to early 1881. If you let me know who you are looking for and when, I can check a couple data bases.
The parish church likely has their records up to the present time. Here is a link to the parish. http://cashel-emly.ie/our-diocese/parishes/e-k/killenaule-moyglass/
Roger McDonnell