Hi,
You might be interested in the following archeological info: http://www.islayinfo.com/carved_stones_islay_index.html
Good stuff:)
Especially this.
This looks really interesting, thanks for the effort of scanning this in. Also came across this 1934 article on the Duns of Islay by V.Gordon Childe http://ads.ahds.ac.uk/catalogue/adsdata/PSAS_2002/pdf/vol_069/69_081_084.pdf