From the original shelbys that I've seen,the letters were black, with a red "P" in the lower [A] pillar area above the two door jamb switches. Often, would have an inspectors name ink stamp with in the paper stamp. NPD sells the correct style paper stamps[part #D-MC136C], some of the other ones for sale look to be too large or have rounded corners. My understanding is that only the shelby used the red "P"in the door jamb.