Bronze wool and motor oil. Rub lightly on the rust spots only.
The best preservative is a microcrystalline wax like Renaissance Wax. Second best a heavy grease like Penn Reel Grease or RIG. You need a complete coat, inside and out. I also use anti-corrosion no-rust bags, sealed with mylar shipping tape - you just have to be careful not to have any oil on the gun with them, just grease or wax.
Golden rods just keep the humidity down, prevent condensation.
For the mold a quick wipe with a slightly damp cloth with a little bleach, then let it dry completely before preserving. Most of the products designed to remove mold will damage the wood.
I swear by Jupiter Optimus Maximus .... in the army of the consul Lucius Quinctius Cincinnatus and for 10 miles around it I will not steal anything worth more than a sestertius in any one day.