I was slightly confused so listed the following
1860 from Griffiths Valuation see
http://www.failteromhat.com I only listed out those Ewing in Errigal Keerogue civil parish
Ewing Robert Ballygawley Errigal Keerogue Tyrone
Ewing Robert Ballymackilroy Errigal Keerogue Tyrone
Ewing Robert Green Hill Demesne Errigal Keerogue Tyrone
Ewing Samuel Ballygawley Errigal Keerogue Tyrone
however for description of property and a map of homestead use
http://www.askaboutireland.ie/griffith-valuation/The Irish Tithe-Applotment-Books – originals in PRONI Belfast see
http://www.irishgenealogyhub.comArdstraw
Ewing, John Tl: Killydart Yr: 1834
Ewing, Robert Tl: Priestcess Yr: 1834
Ewing, Samuel Tl: Magheracotton Yr: 1834
Camus none
Clogher see
http://www.irishgenealogyhub.com/tyrone/tithe-applotment-books/parish-of-clogher.php#.VZbn0EuDoYUEwing, John T: Dunbigin Y: 1825
Clonfeacle none
Donacavey
Ewing, Saml. T: Drummond Y: 1827
Dromore
Ewing, David T: Knocknahorn Y: 1834
Ewing, Jno. T: Knocknahorn Y: 1834
Ewing, John T: Carnalea Y: 1834
Ewing, Wm. T: Knocknahorn Y: 1834
Drumglass none
Errigal-Keerogue none see
http://www.irishgenealogyhub.com/tyrone/tithe-applotment-books/parish-of-errigal-keerogue.php#.VZblFkuDoYULeckpatrick
Ewing, James T: Tenements Y: 1826
Ewing, Jas. T: Roundhill Y: 1826
Termonmaguirk none
Urney no list shown
Hopin that shows going further back maybe possible.
Good luck JimG