If you are sure its a 2001 Proton then yes the bearings are easily replaceable. They use the same bearing (ball and race) that all the O/S hubs used from 2000ish through 2006. Part # HB-RE023.
Bike shops should be able to order them from the bigger Campy distributors. Like QBP Oschner and Hawley.
For questiions like this you can refer to Campagnolo.com where the have pdfs of their spare parts booklets going back at least 7-8 years.
