Yes, I had purchased what was IN a box and presumably was a NOS COUPE Rear Window weatherstrip but found no identifying markings to support the "previously opened" package as being genuine NOS upon initial inspection. Further investigation proved to match up enough to the same as other NOS rear window weatherstrips presently on the market KNOWN to be New Old Stock genuine Ford so I resigned to believe that what I had was genuine. (no Ford engineering number present) There seems to be only the corners have a number like "2" or "4" molded onto them, no other engineering marks have been found on these strips (unlike windshield or other ones elsewhere on these cars)
I could NOT vouch for original assembly line weatherstrips (again, on a COUPE) since mine had been replaced in the mid-late 80's with a new vinyl top installation and is no longer available for inspection.
Richard