In 1881 your Thomas was living in Clara
See: Slater's Royal National Commercial Directory of Ireland 1881, on the Tullamore Page
Your Thomas Delahunty’s death [full description, cause, place, notifying person] can be found at
He d. 16 Jul 1885 at Erry, which is a Townland immediately outside of Clara, on the road to Ballycumber.
See the Free Government Civil Registration Site: -
https://civilrecords.irishgenealogy.ie/churchrecords/images/deaths_returns/deaths_1885/06277/4798556.pdf
Before Independence that Townland was known as Erry Armstrong, having been renamed in a typical vanity by the local Armstrong family!
At time of death he is described as 59 years. Ordinarily I would be cautious of Death Certificate Age, however Policemen’s ages are usually accurate, therefore you may assume he was born 1825/ 1826. I do notice that his wife, the notifying person, was illiterate, so that factor adds an uncertainty to his precise age.
Unfortunately. Clara and Horseleap Parish commence Feb 1845.
https://registers.nli.ie/parishes/0916
Kilbeggan would have been the Post Town, or closest big town
Those Catholic Parish Records are available free at: -
https://registers.nli.ie/
However no RIC man could serve in his or his wife's parish.
A Thomas Delahunty is b. 02 Apr 1827 in Moneygall, s of Roger Delahunty & Ellen [sic] Cosgriff, which is most likely Cosgrave
https://registers.nli.ie//registers/vtls000634656#page/1/mode/1up
The RIC Records are complete, unlike their sister force, the DMP, whose records were often lost, stolen or destroyed, apart from just a few books
http://www.nationalarchives.gov.uk/help-with-your-research/research-guides/royal-irish-constabulary/
RIC men have been indexed by Jim Herlihy, The Royal Irish Constabulary: A Complete Alphabetical List of Officers and Men, 1816-1922 (Four Courts Press Ltd, 1999).
Using the Warrant Number found in that index it is possible to trace the Personnel File in either the UK National Archive or using copies in Church of the Latter Day Saints Family. History Centres
To find a grave search the local newspaper for a Death Notice
https://www.johngrenham.com/records/newspapers.php?county=Westmeath&search_type=full
Or search graveyards closest to where he died
https://www.offaly.ie/eng/Services/Heritage/Archaeology/Burial-Grounds/
Four are listed at
https://www.findagrave.com/cemetery-browse/Ireland/County-Offaly/Clara?id=city_229916
There is no content listed there yet
If an RIC man was a pauper at time of death his comrades would club together to raise a stone to his memory.
And Good Ancestor Hunting
Michael Dixon