One of the easiest ways to remove patina from specific areas is to use polishing papers - I like to use the blue one. You could also use a very fine salon board to remove the patina from the 'high' areas.

Use a burnisher - steel or agate - to shine up hard edges.

Linda Kaye Moses has this tip:-

If you want your entire piece to be given a patina, but don't want it to be black, here's a solution (no pun intended). Dip the entire piece in the LOS solution and allow it to become flat black/grey.

Dip a 100% tightly woven cotton cloth in a little olive or canola or corn oil ( a little goes a long way). Old cotton dress gloves work beautifully, because you can slip one hand in one and dip an index finger in the oil.

Next touch the oiled area on fine grit (extra fine grit is even better) pumice. You can get this from woodworking suppliers. You only need a little on the tip of the glove finger or on the cloth.

Wipe this across the surface of your piece, removing the darkened patina on the surface only. You may need to re-pumice/re-oil clean areas on the glove/cloth. This will leave the dark patina in the letters or in any recessed areas.

Wash the piece in warm water with a mild detergent.

Wipe the surface with a Sunshine Cloth (or an equivalent polishing cloth) for a bright surface on the piece.