I have a 1983 Hunter 34. There are three blocks on swivels at the base of the mast, each with a cam cleat on the bottom. The line comes down, around a tiny sheave or roller, around the main sheave, and then through the cam cleat. The problem is that on all three of them the little roller or sheave at the top has disintegrated. On one it's missing entirely; on the other two, the two side remnants remain (but do nothing). The one on the left (line with green flecks) is the topping lift, and is nearly impossible to haul on. I'd really like to replace these rollers, but I can't figure out where to get them. The two in the foreground are 3/4" wide with a 1/4" pin. The other one is 1/2" with a 3/16" pin. Any ideas where you can get such things? All the local chandlers tell me they have no idea.