i had a look at the national archives site and it doesnt have an online index
(unlike proni),that i could find, but i typed disney in the search and it came up with 1 result.
its in the private sources at the national archives 1972-1997. you can download it as a pdf document but be warned, its huge, with over 1400 pages!
http://www.nationalarchives.ie/pdf/smallprivateaccessions.pdfronnieg,
"index to the prerogative wills of ireland 1536-1810" by sir arthur vicars.
before the fire that destroyed the wills,and the early censuses

,
a sir william betham made abstracts of the genealogical data which was put
into this index in 1897. apparently it includes 40,000 entries! i wouldn't mind having
a look through that book!
tony