They can also be found on Ford's SVT website. Go to Comparison and select '03 Cobra, then at the bottom of the details page are the "official" production numbers by body style & color, but they don't break it down by Interior color. You have to call SVT for that. Just give them your VIN.
But anyhow, you asked "How many have Satin Silver Verts?", I guess the answer would be 81 people