Never use any metal polish no matter how mild it says it is, unless you absolutely have no choice.
ALL metal polishes are abrasive and each use removes a thin layer of plating.
Use too often or just rub a little too hard and you can go right through it.
A good product to preserve and protect the finish is a good NON-AUTO wax.
Johnson's Paste Wax or the high grade Renaissance Museum wax is perfect.
To store, the best place is on a shelf where air is free to circulate around it.
A gun safe with a dehumidifier is perfect, or just a cabinet of some sort.
Worse places to store: In a closet, in a fleece, cloth, or foam lined case, in a holster, or in a Styrofoam box.