fill, smooth and then primer with a spray can, then you could sell "ready to fit and paint" grills.
thing is there are few bravos on the road, and even fewer are owners who mod them, and then out of the modders how many will want a smooth grill, and out of them how many will look on ebay, and out of them how many will be willing to pay your price rather than do it them selves. i'd hazard a guess at 6 sales per year