Joanne.....
the very first thing you should do is call Catalina Yachts customer service. Their number is on the Catalinayachts.com website.Anyway, ask them to send you a replacement parts list. They still maintain a large inventory of C27 parts and the prices are very reasonable. The other website people might refer you to is CatalinaDirect.com but their prices are often marked up over the factory's, especially for mast replacement. Expect to pay $1000 or more for a new spar. Another good source for hardware is GarhaurerMarine.com. They provide a lot of OEM parts for the newer catalina's. They have a very helpful staff. Finally, go to http://www.catalina27.org/ for more info.