Have you ever run across a Thermos Cooker from the 50's in your flea marketing? They're the neatest thing.
The one we have must hold about a half-gallon and is in excellent shape inside, the glass liner is intact. PA rubbed the worst of the rust and a little of the finish off with steel wool. Since we're not interested in selling it, the sprucing up's effect on the value doesn't bother us.