Try 1824 Pigot's Directory on www.failteromhat.com
Too many Jackson's in the telephone book living in the City of Dublin (postal codes) I try Tudor's but you get with the phone book all names first and last that begin with T. I don't have the patience to weed the Dublin ones out.
United Kingdom+Ireland+county (City)www.igp-web.com
+ county ( in these two resources are diffent types of information, some baptism records, tithes, etc. Look for the archives for gravestones/burials
Clontarf Cemetary www.findagrave.comwww.ancestorsatrest.comwww.interment.net
google Clontarf graveyard-Dublin and many places to look for information