Dullcoat will reduce the visibility of very fine scratches, but if they are really that visible, they will be visible even after dullcoating. Cleaning up with fine sandpaper (1000 or 1500) before dullcoating would be a better bet. Be very careful of sanding over decals, however.
Also, you might try filling the scratches with paint. This requires either a super fine brush and excellent brush work, or the tip of a sharp toothpick. At worse, you'll have to sand it if you apply too much paint, but then if you don't try that, you'll have to sand anyway.