Thank-you for all these maps. They're extremely helpful.
As to the U5 in Italy, I know that Brisighelli et al found total U in the south at up to 20%, and up to 28% total U in the southeast. Were you able to use their data and break it out? Did other studies perhaps have far lower levels?
It generally seems to me as if the U5 was pushed north and north east by the farmers, with perhaps some back migration from Slavic areas into the Balkans perhaps? That might explain some of the numbers in Greece as well, although as I said, Brisighelli gave the impression that U was much stronger in southern Italy.
Some of the refugia areas seem to make sense...Brittany as sort of a finisterre...one near the Caucasus...Sardinia.
I don't quite understand the slice around Perpignan(?)... Narbonne)?)... unless that's a bleed over from the Pyrennees.
Speaking of Sardinia, I don't know if the models that see it as totally Neolithic are correct...there are some signs of Paleolithic presence there. These levels of mtDNA U5, and the y dna I2a1(?) if that is indeed Mesolithic, would seem to indicate otherwise. That's certainly the view of Francalacci.