Hi Thomas . .
Welcome to Ireland Reaching Out . . . and . . Roscrea Town . . .
Thank you for your query . . which we will try to assist with . . but. . we are not sure exactly what it is you are seeking . .
We searched Roots (paid) and Ancestry . . . with your given info .
I have posted ( see below) some of what we found . . . . . . which we hope will be of some help in your search .
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Roscrea . . the Town . . is situated in County Tipperary . . but . . on either side . . by a mile distance are . .
the Counties of Offaly Co. (a.k.a Kings Co ) . . . . and Laoise Co. ( a.k.a. Queens Co. )
this makes for very diffacult searching . . . especially when it comes to outlying country districts . . .
you mentioned . . . - Riverstown - this is a village on the outskirts of the town of Birr . . in Co.Offaly . . .
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The first two files (below) are duplicated . . one with NO parents . . bur then the second shows the parents . . which may be new to you
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A Patrick Bergin . . . Death . . appears on Ancestry . . . age 76 . . in Roscrea . . .in 1897
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There is a professional (paid) . . service . . . at. . . https://www.tipperarycoco.ie/heritage/nenagh-heritage-centre
I am not sure if any of this is of help to you . . . .
Best of luck with your search . . .
Cheers . . . Eamonn.