Historical centres of string making

I have been recently doing some research into historical stringing of instruments of the Baroque era, paying particular attention to three theories that I feel require further scrutiny: 1) equal tension stringing, 2) wound strings and 3) loaded gut strings. Hopefully I will be able to publish my findings. To make more sense of these locations, I have made a map listing all the cities that were famous for gut-string making. These cities are: Lyon, Strasbourg (France), Nuremberg (Germany), Leghorn, Pistoia, Bologna, Padua, Venice, Rome and Naples (Italy). I am certain there are quite a bit more, but these are the cities that were mentioned by the Baroque sources I consulted. Perhaps the more sought-after strings were made in these cities.