I modeled up a pattern for the drivetrain pulley and cast some up. Here I am machining one of them.
Here is the set-up. The smaller pulley on top was made from an existing pulley that I had bought for something else and decided to machine it up for the lathe. Everything is as Gingery described it in the book. The belts are for vacuum cleaners. I found them at a local Fleet/Farm store.