I have been around the world and back again and the simplest soil leveller I have ever seen is a primary tillage cultivator - called different things in different countries, but a spring loaded cultivator with points that tills to whatever depth and width you choose, or more likely have the power for, followed by a toothed harrow and a tree trunk (diameter purely optional but usually 6 to 8 inches is enough) on short chains behind the harrow. Cheap, not particularly beautiful, but it works. If you still have clods then flat boards, say 6 or 8 by 2, maybe half a dozen of them bolted to a couple of runners to keep them in place, weighted down if necessary, and dragged over the surface usually works a treat. I have a neighbour who finishes off by standing on an ordianry delivery pallet and having his two donkeys pull it. For a really fine finish and firm surface for grass sowing - the secret of a good lay is a firm bottom, I usually have a heavy chain dragging along last of all. As they say "Necessity is the mother of invention". Old McDonald.
