Rust Question

[drober05]

Here is another question that probably comes up all the time but I'm going to ask it anyway.

I've been looking at Airstream Classic motorhomes from the mid-80's (wish I could afford a newer one). Right now I am getting pretty serious about one and I've got a question about rust. The unit seems to have very little rust visible on the undercarriage. In fact, the only rust I have seen is in the pull-out storage drawers. The drawers are the ones that the door doesn't lock on the side of the motorhome but there is a key to open the storage container once it is pulled out. I think there are three of these storage drawers and all of them have quite a bit of rust on the bottom of the storage drawer. They were not rusted through and they felt solid but this got me thinking about where else there might be "hidden" rust.

How big of an issue is rust on these older units and what should I look for?

Thanks!