As fewer pull-type combines survive from their heyday in the 1920s, 30s and 40s, and as crop yields dramatically exceed the harvesting capacity of these older machines, a need has arose for a small to medium combine to help farmers and farming communities raise grain. This machine, the Ag Vance Comet 2.5 prototype was demonstrated at Horse Progress Days in Clare, Mich., last month. As a prototype it is without safety guards and sports an overbuilt chassis and frame. The manufacturer expects to s