Hi,
I know very little about searching for people in ancestral terms. I have, however, found a baptismal record for a James Brandon dated 19/4/1786.
His father was William Brandon, mother was Elizabeth. Lived at Gortnagullion (written as 'Gautnagullen' ).
This is in BIRTHS RECORDED IN ST. MARYS CHURCH, ARDESS (Parish of Magheraculmoney) Co. Fermanagh
http://www.igp-web.com/IGPArchives/ire/fermanagh/churches/ardess-bap-01.htm
I hope this is of some help. You might also search Tubrid Parish Church records.. These Townlands might be of interest: Glenvannon, Gortnagullion, Drumnagreshial.
I hope this info is helpful. Good Luck
DJ