My wife has just inherited a rem 600 in .308. It has been sitting for 20+ yr. It is really dirty rust on bolt and some on receiver and barrel. Also severe dust on front lens. Question is what would be the best method for removing the rust on bolt etc.. Maybe a real fine steel wool or something similar. Or a solution of some kind. Poss canned air to remove dust from lens and maybe a lens cleaner. The scope is a leapold mountaineer 4x so lenses are small. Thanks for the help.