North Italian is the academic HGDP sample which consists of a small group specifically from Bergamo.
N Italian are volunteers to Dodecad from Northern Italy. In the early days of the project there was a thread where people could state where they were from...otherwise, Dienekes respected their privacy. All four grandparents had to come from that region.
From the ones I remember responding, quite a few were still from Lombardia, just further south, one was from the northeast if I remember correctly, but no one from Emilia or Romagna or Liguria that I remember.
Fwiw, the samples are very similar, with the non-academic sample being just slightly more "northern", probably because of the Veneto sample.
'K12b' spreadsheet - Google Sheets