Flyboyj is right--it is the radiator. The early Mustangs had a "combination" cooler with the oil and coolant radiators together--just different sections. The radiators were located in the belly, just behind and below the cockpit--it the familiar scoop evident in pictures. From your pictures, it looks like you have both sections as well as a part of the propellor hub--but it is hard to say with just the one picture I can see of that part. If you need additional information, feel free to PM me...