http://www.brezzisamuele.com A variety of quality reproduction parts for your vintage Italian machine. Do yourself a favor and put a parapalle at the top of your list. Fast shipping to the US via DHL.
https://www.ebay.com/str/santodimotocicli The King of Italian NOS in the US. If you don’t see it in his store, shoot him an email! He may have it.
http://motoitalia.parts/ Leslie is the nicest guy in motorcycling. He is known as the man for Aermacchi stateside. However, he also has a large collection of manuals and other components for an array of Italian machines.
http://www.guzzino.com Paul not only sells NOS and reproduction items here in Southern California, but he was also a participant in multiple Giro di California events!
https://www.startgomma.com/ Lots of rubber options. They cover many brands, from Gerosa to Olmo and beyond.