Helga,
There is a Dromore in Co Down and another one in Co Tyrone. Both are parishes. You have mentioned Granan in Dromore. I suspect that’s more commonly called Greenan which is in Dromore, Co. Tyrone.
Derry/Londonderry’s parish is Templemore. There were still Sproule households there in Griffiths Valuation c 1860. Charles had a 282 acre farm (which was very big by Irish standards). There was also James (of the Brae), a James senior of The Holme, Oliver, & a Hugh. 1901 census:
http://www.census.nationalarchives.ie/pages/1901/Tyrone/Greenan/Greenan/
Strathroy will be in the townland of Straughroy which is in the parish of Cappagh. Buchanans listed there in Griffiths Valuation but none by 1901.
BBC Radio programme about Strathroy House and a WW1 aerodrome there:
https://www.bbc.co.uk/programmes/p03fyvyf