Beuatiful car! I did the same to my 400E grill, a subtle but very clean difference.
Here are the part numbers for the filler panels with no wiper arm holes:
124 889 05 63
124 889 06 63
They are just over $6.00 each, unpainted.
As for the beam pattern, is your example (_/) suppposed to be the looking down on the front of the car with the beam shining on what would be the right edge of the road? What does "_/" represent?
Hope this helps,