Kaelyn,
I am afraid that I completely disagree with GritDog. Asking questions is the correct thing to do. Here and the other RV boards is a great place to ask them.
Some mentioned evidence of water leakage and there is a good reason. Most coaches of this period have a light wood frame to which they staple the aluminum sheet. If any water gets in, that frame goes away. Even if a water leak gets repaired, the damage may have been done. Get a friend to go with you and look at it.
This is not to say that if it does not have visible water you will not have issues to deal with, any thing and everything can have problems.
If you have the drive and are a capable technician or willing to learn, there can be lots of great deals to be had.
Matt