I am of the same branch of Giffen's referred to in the book "Sentry Hill -Story of an Ulster farm" and also the book written by his grandaughter Isabel Crozier (sister of Joe McKinney Dundee) who lived at Sentry Hill. There was a TV programme made by Ulster TV IN THE 1980's based on the book which unfortunately I have never managed to get a copy of.
Isabel's book William Fee McKinney of Sentry Hill ISBN No 0/9481/54 00 4 has detail of the Giffens. Also see http://en.wikipedia.org/wiki/File:Giffencastle.jpg
which is in Ayrshire,Scotland --passed by there just yesterday with the Giffen Owl from the original castle sitting on an adjacent mill building.