As an update:
The Dwyer sheaves were as expected and I did have to modify them on my drill press for different bushings. I found 1/2"ID x 3/4"OD x 1/2" long bushings at the hardware store. The 5/16"ID x 7/16"OD x 1/2" were difficult. I found them at an automotive electrics shop. this was the smallest he had and he had the one choice. bu, it was perfect.
I had another, thought-- i can buy a 2-1/2" dia acetal rod a foot long for about $25. I could cut sheaves to my heart's content on a lathe that would fit anything on the boat.
-joe
