We just found a John Deere as well; only it did not want to work.
After the first day we drove over some concrete and punctured a tire...$3500 to fix that. Then the next day noticed the smell of diesel fuel. After a little investigation we found the radiator full of fuel. The John Deere's have seals in the injectors and the fuel was blowing into the coolant at high pressure thus filling the radiator. It only cost $270 for the injector seals, but $1700 dollars in repair costs to get the thing running again.
Which ran for 15 minutes before it started skipping. Come to find out the fuel went in the radiator and the coolant went in the fuel tank. It took a few hours to blow out the fuel lines, drain the fuel tanks and then get the filters changed, but thankfully the engine was sound through the whole ordeal. Either way corn fields sat unharrowed for 3 days waiting to get Green Giant up and running again.
She's running good now though...130 acres on Thursday. 115 acres on Friday and about 8o acres and counting today. First crop of grass is already in, crews are already spreading manure on the grass ground, and we should have all the corn planted by early next week. It has been a good year, well except for the price of corn seed, but I guess you get what you pay for.