I am a woodworker with many years exp in furniture and cabinet building and finishing. I have built most of my wooden furniture at home and for others. I have built and matched finishes of new cabinets to match existing cabinets. I am not the final authority but I can tell you that you had better leave the planes, scrapers,sandpasper, steel wool and any other abrasive alone. There is no way you can get the scratches out without refinishing the side where the scratch is. Therefore your alternative is to hide the scratch as best as possible. You said they were hairline scratches. It has already been said, that you can use Old English furniture polish. This is correct. Old English has stain in it and that is what hides the scratch. Another alternative which i like better is to get some matching stain and use it. Don't worry about getting it on the finish of the cabinet. There should be a clearcoat of some kind (probably oil) which will keep the stain from penetrating any area except the scratched area. Just wipe it on and wipe it off. Let it dry. Repeat until you get the right color. Remember you can make it darker but you can't make it lighter. You should have no trouble at all. Depending on how dark your cabinet is the scratch will probably cover first coat. remember perfection is not possible at this point. We are trying to camaflage the scratch. Best of luck to you.
