https://www.amazon.com/Corrosion-Pro...71580015&psc=1
Fluid Film, comes in aerosol, and can also be purchased in gallons if you care to brush it on. or spray with a spray gun. It's the same formula used to undercoat cars in the rust belt to stave off the salt, and salt spray on undercarriages. it will also penetrate into cracks and crevices. It's wool wax, not grease or oil based.
Years ago I also used wire rope and cable protector on bare crankshafts etc. I have cranks that were sprayed in the mid 80s still protected with it.
Bagging something in plastic is a 2 edged sword, it can keep out moisture, but it can also hold in moisture. I cover things to keep dust and dirt from accumulating, but air can still circulate around the item.
Iron gets cold and when subject to warming up sweats and draws moisture, same as the mirror in the bathroom does. I tried sealing metal parts with plastic bags and caused more damage than I did good. Ideally you have a temperature controlled environment to keep the iron from getting cold, but few of us can afford to heat our garages in the north 24/7.