I am repairing a 20 year old silver eagle and I am new at this but from my experience so far, what ever damage you see is in far worse shape then you think it is. The hidden stuff I keep uncovering is mind boggeling, especally with rot and rust.. Be careful and expect to spend more then you think you will.
If I ever do this again I will buy something that is used regularly and well maintained.
I have learned that if you see evidence of a Leak, the damage is worse then you think,
If the seller cannot operate every system on the unit and show you that they actually work, they probably do not. By every system I mean does it have fuel in the gas tank, does the motor run and drive and Stop. LP in the LP tank and water in the fresh water tank so they can demonstarted that everything that uses LP or water or both actually works.
Everyone I ever spoke to selling old RV's all said it all works but almost every one had either no water in the tank, No LP in the Lp tank or said all it needs is a new battery or a freon charge or a tune up
Be very careful. Let the buyer beware