If you think this Best 60 looks somewhat like an early Caterpillar Tractor, its because it's true. Best and Holt were merged in 1925 to form Caterpillar. the Sixty is Best model that carried over into the Caterpillar line. this machine is on display at "Camp 18", a restaurant and logging museum along US 26 out of Seaside, Oregon. These tractors were originally used as farm tractors mostly, and my guess is that the blade was added after World War II.
At that time, the model number was more or less reflective of claimed horsepower. It was started with a bar in the flywheel---you can see the notches for it, and you will note that it has a gasoline engine. You can see the coil and spark plug wires.