About this 3D model
Wow! it's been a long time since I worked on these. But I did notice that there were a few of the files missing -- so I uploaded them. Make away! I made the Block and Tackle - Pulleys by SteveWall with two variations -- instead of using wooden dowels, I made a second pulleyplate adding the "dowels" to it, making a male/female assembly. I also used a single 3mm x 22 cap screw in the center to fasten it together. I've now added the half-sheave as requested.