Greg,
Now I am not trying to tell you what to do, but if it were me, I wouldn't sell it to him. I wouldn't sell any original tractor to anyone unless I know for a fact they are going preserve its history. Everyone of these antique tractors has a "story" to tell and if you repaint it, to me anyway, that story is gone. I have seen some original tractors bring more at sales than if they were repainted. The only time I would repaint a tractor is if there was no way to save the original paint. As a fellow friend and collector told me one time, "they are only original once".
Cheers,
Dakota