I know this has probably been talked about a 100 times on here, but here it goes again. I am looking at buying a 4020. I believe it is an early model as the hydraulic controls are on the dash. It is an open station with decent fenders. Sheet metal is fairly straight, but paint is all gone. Tires are pretty wore out, and none of the gauges work. Fires up pretty good, and has a power shift that seems to shift through all the gears good.It has a big hydraulic oil leak coming from underneath the hood. I'm not sure what or where it is coming from, or how hard and expensive it will be to fix. This guy has just used it to bale 10 acres of hay for the last few years. He is asking $5500. Whats your thoughts on that? Any idea what the leak might be, is there a common problem that leaked on these? I have always loved the 4020 and dreamed of owning one, but don't want to buy a headache. Any thoughts are appreciated. Thanks