mwb posted:Dilute Glacial acetic acid ~50%; immerse for 15-20 min. A soft brushing may be necessary to remove heavier tarnish.
Rinse 3-8 times with pure alcohol. Air dry and paint (!) ...
paint would be my suggestion, too. it's easier to remove fresh paint than to clean up a tarnished brass surface and who knows, you might get it right the first time. a poorly painted brass model is usually a horror, but a nicely finished brass car, painted and decaled, enhances its appearance IMO. ...frankly, i'd prefer a light weathering, too.
cheers...gary