how about.......
...any local marine store. Here's Defender online if you like internet shopping.Cam, clam, horn, jam http://www.defender.com/category.jsp?path=-1|118&id=295771or spend the big bucks on rope clutches.http://www.defender.com/category.jsp?path=-1|118&id=3800 Get the size that fits your halyards... probably 3/8" diam. the C27 association website has all specs and parts lists.http://www.catalina27.org/