My dad and I are seriously contemplating a used 9660. It has 950 sep hrs on it. Appears to be a beautiful machine. I have tried hard to educate myself on these machines (all new to me, I have an 860 Massey now). What should I look for on this combine? I have read about reverser problems on John Deere machine. Hell, I don't even know what a reverser is! Are there any serious issues with 9660's? Any problems with that year? Anything anybody wants to throw at me would be appreciated.