This Looney forum has been most interesting and informative. Well done.
I refer to your preference of Thomas Looney b. 1740, Ballamoar, Lonan. This Thomas married twice, Could Elinor Costean been working as a housekeeper for him, hence the involvement?
Thomas Looney b.1773 (his son & heir) married, 1800, Santon, Ann Brew, daughter of Robert Brew, Meary Veg, Santon & Isabel Moore. Their son & heir, Thomas Looney b.1801 died unmarried.
Discovering 'lost cousins' has sent me on another line of research.