I had a Keen rib on a Perazzi that shot way too high. Instead of cutting the comb down I added a rib of the height equal to the amount I would have had to shave off the comb. Worked like a charm and looked ok. The original rib was flat and the add-on looked like it belonged there. Keen uses an epoxy that allows you to remove the rib with a piece of monofilament worked between the add-on and the original rib. I recommend Keen highly.