Iņaki asked:-

Where did you get all this info from? Im interested. Did it only mention mention the basques? What about the Galicians?
Much of the info came from the following two population genetics research papers:-

http://www.ucl.ac.uk/tcga/tcgapdf/capelli-CB-03.pdf

http://popgen.biol.ucl.ac.uk/PDFs/35.pdf

WARNING: A lot of the data contained in these papers is of a highly technical nature, so it is best to skip much of it and read through the Results and Discussion sections.

I think there is enough here to be able to rule out any possibility of tartan kilts being brought to Scotland by a mass migration of Celts from Austria. However, the evidence is strongly in favour of the Northern Iberia to the British Isles post Ice Age migration theory.

Regarding your question of whether Galicians could also have been involved in such a northward migration, if there is a close genetic similarity between the Galicians and the Basques, then it would indeed have been possible. Certainly Galicia has a culture, which has been identified by some as being Celtic. However, any such migrations would have been far too early to have involved the transfer of a tartan kilt wearing culture from Iberia to Scotland.

Rob