Re: C&C Halyard Sheaves
I pulled the sheaves from our C&C a couple of years ago. The bushings were badly worn but easy to replace. A good hardware store has standard bronze bushing that you can press in with a vice or C clamp as you push the old ones out. Use a short section of pipe or a socket to provide room for the old one to come out.
Since I was changing to rope halyards, I put the sheave on a lathe and used a 1/2 inch rotary file in a drill motor and reshaped the grove from the V to a U. A decent machine shop can do it easy enough but it looks like the best offer comes from Tyrannus.
I wanted to keep the aluminum sheaves because I didn't trust the delrin sheave to keep their shape under prolonged tension and
RigRite was way too expensive. If they're badly damaged, I'd talk to a machine shop and have some new ones made or try the delrin sheaves.
Rope halyards are the only way to go. I got tired of bleeding all over my sails from meathooks on the wire.