I am currently looking at a '59 Minn. Moline 445 that is for sale in my area. I am looking for some advice to make sure I make a smart purchase. It's a '59 it has the 40 hp gas 206 engine. Old tractor used to be a backhoe but the hoe was removed. The seller said, "it does start and run but smokes and knocks. I think it only needs rings and rod bearings. The tractor is old and used probably missing a bolt or two here and there but starts really easy and runs good except for the smoke and knocking. If you are handy probably take an hour to fix it." I am wondering from those of you who know these tractors, what do you think of the "smoking and knocking" is this something that can be fixed easily or I am looking at an engine rebuild if I buy this tractor. What would you consider to be a fair price?