I'd suggest you post a picture of it in the C&V section of the forums. There are some good folks there with experience with older Bianchi's. Someone probably has a good idea of exactly what you need and the cheapest place to get it. Someone else's idea of going to a bike shop is probably the best idea, however. Getting the job done right by a professional is sometimes cheaper in the long run (and usually safer) than doing it yourself several times.