Inspection of the masthead sheave (pully-wheel-thing inside the top of the mast) shows that it is somewhat worn. Though it still seems to be mechanicaly sound I would like to replace it along with the spreaders and spreader bases that i now have parts for. Dwyer aluminum mast company has aluminun replacements (were I purchased two spreaders thanks to Commanderpete). Does anyone have any experience replacing the sheave, or any suggestions?