The lower anvil in my project is a pillow block bearing, which has a curved outer edge perfect for this application. The anvil is held on a pin which is placed on a U-shaped holder made of 1/4" steel plate. This holder is welded to a 4" long steel pipe. The other end is connected to another small plate with a rod welded to the bottom of it. This rod, along with the two guide rings at the top, allow this entire assembly to move up and down inside the guide housing when the handle is turned.
At the bottom of the guide housing there is the threaded rod guide. This plate with a 3/4" threaded hole in it is the only part that holds the adjustment rod. The adjustment rod presses directly against the guide rod that is connected to the moving assembly.