To me, that's also 2 strikes with the dealer. One, to sell the tractor like that....UNLESS there was a serious discount. And full disclosure why it looked like that. Second strike was to wirewheel some metal, and spray oil on it?? Really??
As others have said, there much more to the story here than we know. Need more info from the OP.
And to say that's acceptable....? I think not. It's got issues now as a new machine, think of what will happen at time goes on.....and when the warranty ends...
Unless the OP knew about the corrosion and the purchase price was signifigantly reduced, I would get rid of that thing ASAP.