Count the columns. D Grill must have exactly 15 columns.
Just by looking at the front, one fact also in your favor is that it is the dull rose shade, and all of the "experimental" grills (A,B,C,D,Z) are only found in the dull rose shade.
Good luck...there are definitely D grills out there to be found...I've found 3 of them on
ebay, including one unused in the past couple of years (all ID'd as E grills, BTW).....
Ray