You cant buy one, you would have to make one, as as far as im aware, the grill was unique to the car. A few people have done it themselves, its not that hard, you can buy the mesh on ebay.
I Cant think of anyone on here who has got a debagded grill. Ive got a grill Dal gave me which im planning on doing at some point. Its a case of cutting the middle out of the grill, and wrapping mesh over the remaining outside shell.
I've been planning on doing a de-badged one for a while now and even picked up a cheapo second hand one. Basically going to cut out the badge and replace it with a section of normal flat grille to fill the gap. Then tidy it up a bit to make it nice and smooth
Morts suggestion is how i've heard people do it before.
To be honest if I were going to do it i'd want 3 grills, 1 original leave alone, 2 as a donor to 3, 3 for cutting out ford badge and bonding plastic in from 2