I have the opportunity to buy a 1977 Scout II Traveler with a 345, less than 30k miles, from a trusted person. He replaced radiator, hoses, tires, etc. However, the car was sitting since 1991 in a garage, not being used since. The engine runs ok as much as I can tell. However, should I be concerned that the cylinders have rust from the piston rings? Any other concerns? Thanks.