Making an assumption that the families were Church of Ireland.
A Irish History Foundation has the parish records for Modreeney.
Parish Modreeney (Cloghjordan) baptisms 1846-1911, marriages
from 1845-1911, deaths 1827-1911
If the deaths are inscriptions not just entries of a death in a parish register then you may be able to get some family information. The gravestone inscriptions are another
place to look for family background often there was enough information for a family tree. There would be a Heritage
Society or Museum or Library that may have these. Most likely you would need to purchase a Journal from a Heritage
My husband surname Code/Codd is related to the Dagg's of Wicklow that went to Lanark Co. Upper Canada. Staunch Protestants. I was fortunate to be able to get back to 1813 and record prior to that non existant.
If they left Ireland before 1819 they would not even be in the Tithe Applotments 1820-1839, a census substitute. You should be able to find those that stayed behind in the
1850 Griffith Valuation. www.askaboutireland.ie
There are also 5 Dagg's in the Tipperary telephone book,