I apologize as I probably misunderstood you.
Are you saying Ligurian is proven non-Indo-European?
Are you saying everything in SW France (Aquitaine) and Iberia was non-Indo-European until Roman times?
If the answer to either is yes, please explain. I looked at your link to a google/books page or something but it was restricted. Please explain the key points of your proofs directly.
"Celtic from the West: Alternative Perspectives from Archaeology, Genetics, Language and Literature" by Koch and Cunliffe, 2009. I'm sure the books from the 1800s and 1960s are very nice, but this is a very recent book by two highly esteemed authors and legitimate authorities. They have access to the latest dating, archaeological and linguistic data. They are a bit behind on the genetics though, but at least they thought about it.
This book is an exploration of the new idea that the Celtic languages originated in the Atlantic Zone during the Bronze Age, approached from various perspectives: pro and con, archaeology, genetics, and philology. This 'Celtic Atlantic Bronze Age' theory represents a major departure from the long-established, but increasingly problematic scenario in which the story of the Ancient Celtic languages and that of peoples called Keltoi 'Celts' are closely bound up with the archaeology of the Hallstatt and La Tene cultures of Iron Age west-central Europe. The 'Celtic from the West' proposal was first presented in Barry Cunliffe's Facing the Ocean (2001) and has subsequently found resonance amongst geneticists. It provoked controversy on the part of some linguists, though is significantly in accord with John Koch's findings in Tartessian (2009). The present collection is intended to pursue the question further in order to determine whether this earlier and more westerly starting point might now be developed as a more robust foundation for Celtic studies. As well as having this specific aim, a more general purpose of Celtic from the West is to bring to an English-language readership some of the rapidly unfolding and too often neglected evidence of the pre-Roman peoples and languages of the western Iberian Peninsula. Celtic from the West is an outgrowth of a multidisciplinary conference held at the National Library of Wales in Aberystwyth in December 2008. In addition to 11 chapters, the book includes 45 distribution maps and a further 80 illustrations. The conference and collaborative volume mark the launch of a multi-year research initiative undertaken by the University of Wales Centre for Advanced Welsh and Celtic Studies [CAWCS]: Ancient Britain and the Atlantic Zone [ABrAZo]. Contributors: (Archaeology) Barry Cunliffe; Raimund Karl; Amilcar Guerra; (Genetics) Brian McEvoy & Daniel Bradley; Stephen Oppenheimer; Ellen Rrvik; (Language & Literature) Graham Isaac; David Parsons; John T. Koch; Philip Freeman; Dagmar S. Wodtko.
http://www.amazon.com/books/dp/1842174754
I actually don't agree with "Celtic from the West".
I'm just trying to make the point that it is far, far, far from proven that IE languages were not spoken along the Atlantic long before Hallstatt folks.
IE speaking people may have reached this far much earlier than traditional Hallstatt thinking. PIE is much older than Hallstatt and there are artifacts, such as the Stelae, that provide evidence of links all the way from the the Steppes to the Atlantic.