well first off you can tell if it is a deisel pretty easy. if there are spark pluges then it is a gas. by the way you described the tractor i would say it is an industrial. if the grill has no bars going vertical its a 550 if there is one bar down the center its a super 55, but i'm pretty sure the 550s only had the loader backhoe yet i could be wrong. i'm sure you will find engine parts and sheet medal but if the frame is damaged you might have problems but oliver industrials are built tough so i doubt it. anyway i have seen a 550 industrial like this and they are nice tractors to have.