I'm restoring a pair of Cornwalls that need grilles. I ordered the cloth from Bob Crites, but I have a question about the cutout for the grille backer board. Are there separate cutouts for each driver and the port, or do some share a common cutout? My serial numbers are 8407319 and 8407320. If someone could post a photo of the back of a removed grille, that would be very helpful. Thanks.