The Valuation Revision records for Magheragart on the PRONI site show Susan McLoughlin’s name deleted between 1860 & 1863, and replaced by Patrick McLoughlin. Bernard McLoughlin was deleted in 1865 and replaced by Catherine McLoughlin. She in turn was replaced by John McCann in 1872.
Henry McLaughlin’s name remains against the property till 1918.
George McLaughlin changed to Mary McLaughlin in 1864 and then to James Breen around 1872, then to Patrick McLoughlin in 1882 at which time it was land only (it the farmhouse was down).
By 1918 Patrick McLoughlin was tenant of all that land. He was deleted then and replaced by others.
Probate abstracts for McLaughlins of Magheragart who are presumably connected to the families in Griffiths. Taken from the PRONI wills site:
McLaughlin Henry of Magheragart Dromore county Tyrone farmer died 7 May 1935 Administration (d.b.n.) Londonderry 2 October to Felix McLaughlin farmer. Unadministered Effects £1. Former Grant Administration Dublin P.R. 3 November 1916.
McLaughlin Mary of Magheragart county Tyrone spinster died 28 July 1928 Administration Londonderry 6 May to Felix McLaughlin farmer. Effects £75.
Death registration only started in Ireland in 1864 so those who died before that probably have no record unless they are on a gravestone.
There’s a death for a Bernard McLaughlin in 1864 aged 60 registered in Omagh. That might be Bernard. One for George in 1868 aged 48. Neither is on-line free so you have to pay to view the certificates on the GRONI site.
Henry McLaughlin death in 1915 aged 62. Bachelor. Informant was his sister Mary.
https://www.irishgenealogy.ie/files/civil/deaths_returns/deaths_1915/05273/4463906.pdf
Another Henry McLaughlin death in 1892, aged79. He was married. Informant daughter Rose:
https://www.irishgenealogy.ie/files/civil/deaths_returns/deaths_1892/06036/4719093.pdf
Death of Mary McLaughlin in 1871. Widow aged 82. Informant was James Breen (a son in law perhaps?).
https://www.irishgenealogy.ie/files/civil/deaths_returns/deaths_1871/020757/7282054.pdf
Patrick McLaughlin and wife Mary Fee in 1901:
http://www.census.nationalarchives.ie/pages/1901/Tyrone/Dromore/Magheragart/1741604/
And in 1911:
http://www.census.nationalarchives.ie/pages/1911/Tyrone/Dromore/Magheragart/870322/
their 1 child Mary Catherine was born in 1871:
https://www.irishgenealogy.ie/files/civil/birth_returns/births_1871/03274/2199871.pdf