This is the grill I'm looking for! Where did you purchase it? Part number?
It should be very easy to fill the holes with fiberglass (bondo) and paint them gloss black. Texture-matching the 3 smooth rectangles to the other textured rectangles will be much more difficult. Perhaps they could all be filled with fiberglass and made smooth and painted, but I'm not sure it would produce a better result.
I purchased from R8 stuff. I ordered some black ABS plastic .062 thickness that has the same texture. I’m going to cut squares and try to overlay where the holes are. I will post some pics when completed if it works.
What about using SEM 39853 Black Bumper Texture for matching the 3 rectangles? Mask off everything except the 3 rectangles, sand to get a surface with better adhesion, spray-on the SEM texture match, and then maybe spray on some gloss black paint to better color match.