A manx RC called Quirk would I'm afraid be a very unusual beast at least until well into 19th C! - until the 1840's/50's nearly all RC's on the Island were Irish immigrants - there was a small fishing community (tho all say it was Irish) around Castletown and the south that was RC - see http://www.ee.surrey.ac.uk/Contrib/manx/parishes/rcath/rc.htm
for some history.
After that intermarriage generally with Irish, brought more native Manx into contact with RC church.
Quirk is generally taken as a Manx name but many Irish names also derive the same way from Mac to Qu (eg Quin is Irish, Quine Manx)