Old Car That Hasn't Been Started In A While

My wife's grandfather is possibly going to be giving us his Studebaker.

We are concerned about the engine as it has not been used for quite some time(Up to 20 years or more). The car apparently ran perfectly fine when last used.

I am no car guy by any means so any repairs would have to be done by a mechanic.

What kind of issues would we be looking at for a vehicle that has been sitting that long?

We would like to try restore it to as close as new as possible.

Tires, brakes, possible frozen engine, animal infestation and the usual rust issues in the floors and frame, someone knowledgable needs to look this over for an evaluation.