I will reply to this because it was my car for 14 years. Yes, about 10 years ago, I repainted the trunk because of scratches and light surface rust here and there. I also painted the wheel, jack parts, cleaned the trunk striker and spare tire mounting hardware.
In short, I wanted it to look nicer. The trunk has absolutely no rust beyond light surface rust and is 100% original sheet metal.
I don't know why he is selling it, and it really doesn't matter to me, but in my opinion, the only real issue is that the car could use a clutch, or at least I was never happy with my clutch choice.