There are some key places to look at for rust: Rear shock towers are obvious, also look at the front shock towers. See if you can pullup the carpets to look at the floors. Escpecially in the front around the pedal box. Look under the car where the front frame rails join to the unibody at the front floor boards. Underneath in the back where the rear suspension is attached to the unibody. Also down in the engine bay where the front frame rails are located. If you see rust in these places, count on MAJOR dollars to fix. Some other areas include rockers, spare tire well, front fenders, bottom of doors. Those can be cheaper to replace but you can still run into money. It is all about how much you are willing to spend & want to do. I've been there & done that! My 1600 has excellent structural areas that have never been touched (that does not mean there is no rust there), but I have replaced the front fenders, both rockers and the rear wheel arches twice, and the bottomhalf of both doors once. Part of the drivers rear floorboards and small areas of the hood and trunk lids. Been painted twice & after the second time, I retired the car to nice days in the summer. It no longer even sees rain if I can help it. That has really helped to preserve the 2nd restoration that was done about 15 years ago. Good luck & post some pictures if you have the chance!