Don’t try to restore, repaint, touch up, add a clear, protective coating, unknown polish or cleaner, or throw away a tag or a box for an antique or collectible without doing research in current books or online. The boiled linseed oil used by museums in the past to polish furniture crystalizes, can’t be removed, and dramatically lowers the value. Old paint often contained lead or, worse yet, arsenic that can kill you. The more original paint on an antique iron doorstop or toy, the higher the price. A repaint can kill a sale; it is just not wanted by a serious collector. Museums now like to use removeable paint or other coloring matter for restoration and touch up for oil paintings.

But there are some things that are worth more if repainted or repaired. A toy pedal car must be restored by a professional artist so it looks exactly like new, just as you would expect if you had your full-sized car repainted after an accident.

German iron gnomes are popular ornaments usually wanted for display in a garden. There are copies made of iron, cement or an imitation stone. An artistic repaint following the design of the old paint adds to the value, and the gnome will sell more quickly and for at least 50 percent more. An iron garden bench, if cleaned and repainted white, black or dark green, the colors most used in Victorian times, also goes up in price. Be sure to clean off any rust before you paint so the original metal shape and details show.