A couple places to really look at. I wouldn't be worried about that number of hours if the machine has been taken care of. * look at the rotor cage (especially over the grates) look for near wear through, bent supports, other stress. * look very close around the rotor gearcase mounting bracket - if it has been welded or replaced may tell a story of how the combine was treated. * look at the oil cooler in the engine compartment (under walkway),you can easily tell if alot of rotor belts have been blasted into the cooler. * look especially close around the feeder face adaptor for cracks. * look around the front axle and how it mounts to the front posts - that much road time could lead to some cracks and distress around where the front axle is welded. * look over the front bearing support on the rotor, it has been known to crack out. * The rotor transition cone, the front of the cage, and vanes (especially over the concave area) are typically high wear areas. * The boots on the inside of the clean grain elevator and the tailings elevator are also high wear areas. My biggest concerns would be frame cracks. The wear things can all be replaced, its only money. But the cracks will give you fits.