Yeah. I have one of those on my OB. They bolt right up. No drilling. It just didn't look like anythings ever been bolted up. And usually those hitches don't agree with the bumper lips, so I think there would've been some signs on the bumper if one had ever been pushe up against it.
I could be wrong though. It's not a lot of rust. It's just some surface rust here and there and spots of rust here and there. I'll take a pic later. It's weird.