Rust: If you want to do it properly, boil the action and barrel in a tube of water for 25-35 minutes, will convert the rust in a similar way to rust blueing, then steel wool carefully and cover the steel with boiled linseed oil. It will create an excellent long term rust preventative (George White)
Oil stained Stock: oxalic acid will remove them. Get it from a paint shop, it’s what house painters use to remove the same type of stains caused by rust/nails in the timber (Colin Street)
