Here's some plaques I just cleaned. Some were painted so needed stripped, some had been wire wool damaged and some over dipped to the point they had turned pink through the copper leeching out. The Ratner one must be pink brass? I've had it on the polisher and it just won't come through to the gold, it's as if it's that colour right through. I have a couple of George price plates and one of them seems the same. I've seen some advertised on flea bay described as pink brass or bronze but I always thought they had been left too long in lemon juice because I've done so myself. Always comes off on the polisher though. That Ratner has me puzzled.