I have not found anything about Patrick Maguire flying a Mosquito on his service record.
Does it really matters?
Patrick Maguire served his country in WWII. First as a LAC (Leading Aircrafman). Patrick Maguire was born on January 30th, 1923. He enlisted June 11, 1942 and commenced serving the same day.
ACH/Pilot means Aircrafthand/Pilot. That's a general term used when someone enlisted.