[Christ]

Not really structural, though.

They do rot, and it's something to look for, but it's not usually a deal breaker, as it won't make the car "unsafe" to ever operate again. The repair panel for it is very easy to line up, and you can actually repair the area with some sheet metal and fender washers, if you're really cheap.

It just keeps the rear end from swaying back and forth under the chassis by a few inches each side.

I'd still inspect it like crazy, if even just to get a better deal (if there was such a thing) on it. It's an old NY car... it's bound to have rot somewhere.