What were the sources quoted in the book?
Ancestry.com has the following searchable book:
The Original Scots Colonists of Early America. Caribbean Supplement 1611-1707 [Perhaps this would include Scotch-Irish?]
Your best bet would be census data, but I don't know if/when those were taken.
FamilySearch.org has various records for Caribbean countries that you could search or browse. You would need to use surnames,though -- There doesn't seem to be a way to search by birth place.
The Digital Library of the Caribbean might have something...http://dloc.com