Not sure whether it helps or not but there were these 2 Scullion families in Tamlaght in the 1851 census. No McKeowns listed though.
33, NICHOLAS SCULLION, 80 ,Head, Married ,1798 , FARMER ,Antrim ,R/W
ANN SCULLION, 79 ,Wife, Married ,1798 , NONE ,Antrim ,R/W
NICHOLAS SCULLION, 36 ,Son,Unmarried ,, LINEN WEAVER ,Antrim ,R/W
CHARLES SCULLION, 32 ,Son,Unmarried ,, SHOEMAKER ,Antrim ,R/W
JOHN SCULLION, 10 ,Grandson,Unmarried ,, NONE ,Antrim
ELIZA SCULLION, 9 ,Granddaughter,Unmarried ,, NONE ,Antrim
Died Since 6th June 1841:
WILLIAM SCULLION, 31 ,Son , LABOURER , Dropsy , Spring 1847
37, PADDY SCULLION, 46 ,Head, Married ,1844 , FARMER ,Antrim ,R/W
JANE SCULLION, 39 ,Wife, Married ,1844 , NONE ,Antrim ,R/W
ANN SCULLION, 3 ,Daughter,Unmarried ,, NONE ,Antrim
CATHERINE SCULLION, 15 ,Niece,Unmarried ,, LINEN WEAVER ,Antrim
ROSEY McGUCKIN, 13 ,Servant,Unmarried ,, LINEN WEAVER ,Antrim