Cahill Brothers - Patrick (b. 1773) m. Catherine Cody and Walter Cahill (b.1884) and Anastasia Cody (b. 1795)

Hi Mary,  This  is what I found.
I see a Thomas Cahill in  the Tithe records this is dated 1827.
http://titheapplotmentbooks.nationalarchives.ie/search/tab/results.jsp?…
Actual page......................nummber 49.
http://titheapplotmentbooks.nationalarchives.ie/reels/tab//004625702/00…
This is Thomas in 1850  this is from Griffiths Valuation
http://www.askaboutireland.ie/griffith-valuation/index.xml?action=doNam…

When Searching these records look for Tipperary North. (It was split into 2 Ridings)
The Registration district is Thurles

This next site  is free (as are the other 2 above) but having said that if it doesn't say "Image" then you can obtain an image but you would have to pay.
https://www.irishgenealogy.ie/en/
1864 Civil records were introduced in Ireland. 

Now to the Census, 1901 there are Cahill in the same area. Also in the same area in 1911.

http://www.census.nationalarchives.ie/pages/1901/Tipperary/Moyne/Moynet…

www.census.nationalarchives.ie/pages/1911/Tipperary/Moyne/Moynetemple/8…

Looking in Familysearch.org this looks like a brother or cousin to the Patrick and Walter. So all the obove relates to this Thomas.

Thomas Cahill
Ireland Civil Registration, 1845-1913
birth: 1779
death: 2 March 1864
Moyne, Thurles, County Tipperary, Ireland

I hope this is a help, as your info. is well before detailed records.
Margot

Thanks so much Margot!  This is indeed very helpful. 

Very much appreciated :)   I can't wait to visit!

Mary Banman