have some docs about that but of diverse origins and compilations (not 100% reliable I am afraid of):
concerning Y-R1b it seams that the heavier concentration [more than 55%) would be in Lombardia, Emilia-Romagna, North Piemonte, Trentino, extreme W-Veneto - [45%-55%]: Central Piemonte, extreme S-W Lombardia, Friul, C-Veneto, E-Emilia-Toscana, Marche - [35%-45%]: S-Toscana-N-Lazzio- >< [25-35%]: remnant = Southern Italia, extreme N-Sardigna + W-Liguria, at the exception of: the bulk of Sardigna, Sicila, coastal central Campania (Napoli) where Y-R1b would be under 25% - as a whole, for R1b, N-W Italia and N-E Italia are not so typical as C-N Italia (Lombardia-Emilia, where the Celts was sthe strongest)- a survey (limited sample) showed 73% of Y-P*-R1a in N-Lmbardia, 76% of Y-P*-R1a in Abbruzzi, between N-Toscana and Emilia - sure P*-R1a contains other HGs than R1b but it is evident that R1b is by far the strongest componant of it - Even if not totally reliable, these %s seams making sense - for N-Sardigna, we know that Corsica is rich enough for Y-R1b (about 60%) -
but all these %s are confusing in the way that the quality of Y-R1b is not the same at all: more eastern upstream SNPs in Southern italia (linked to HT15) and more atlantic or western downstream SNPs in Northern Italia (akin to HT35) - I suppose that, even if come through South, R1b forms of N-Italia knew a completley different story as opposed to the southern ones -
Y-R1a seams almost absent from N-W Italia (0% in a survey about Liguria), present in Trentino (7%) and strong enough in Eastern-Veneto-Friul (9%: C-Veneti?) - for Piemonte and Lombardia proper I have no source -
I have nothing else about N-Italia and I regret it -
it would be an error considering that Piemonte should be half way between Liguria and Lombardia: I suppose Piemonte is closer to Lombarida even if surely Y-RU106 is rarer in Piemonte, the same as Y-I1, being these markers germanic markers as a whole - Liguria is a very coastal area, and Genova in the Middle Ages was a mighty maritime kingdom with far relations and exchanges -
sorry for this poor contribution, but Italy lacks the great surveys made for Iberia