Once you have everything masked off, you may want to try some automotive chrome cleaner used SPARINGLY on a rag, then work your way up to the other abrasives if that doesn't do the trick. If you use sand paper get the finest grit that you can find (800,1200,1500). If you are going to use steel wool get the finest grade that you can get. After cleaning the posts up I would also recommend a dab of some denatured alcohol on a clean rag and applied to each post before applying the lacquer (clear nail polish is lacquer BTW). This will remove all of the oils from your skin and any remnants of the cleaning. It will also give the lacquer a clean surface to adhere to. Keep in mind that the denatured alcohol may affect the surface of the plastic so take very good when doing this.
All of the above is assuming that the post is a solid material and does not plated. Escobon should be able to verify that.