The instructions have some errors. All kit instructions have errors. Since catheads had two or sometimes three sheaves, I would scratch build some more detail into one of the examples below, and use two sheaves (pulley wheels) separated by a thing square of scrap wood inside the hole you carve out of each side of the set of pieces C6. Instead of using the kit parts C7 for the sheaves, get a dowel of similar diameter, and use a table saw or band saw to cut two, thin slices to make your own sheaves, then use a small needle file to file a shallow groove around each sheave. Better yet, spin the dowel in a drill and cut the shallow groove which accepts the rope first, then slice off the wheel from the dowel with a saw. If you don't have a copy of the book below, you may want to find one. It has so many pictures which allow you to build beyond the overly simplified features found in kits and make your model more detailed.
From
Historic Ship Models by Willem zu Mondfeld
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