I'd guess he had trouble with his upper incisors (sensitive? Decayed roots?) and wrapped some white adhesive tape over the MP to reduce vibration. He might have wrapped several turns around and then cut it off where the reed goes. He could even have put a wet reed on and then wrapped the tape (would have to re-do with each reed change).
You younguns need to keep in mind that this was pre-Internet, pre-mail order saxophone shops. If your teeth hurt when you played and you weren't in easy reach of a music store that sold cushy MP cushions, you improvised. A roll of white adhesive tape is available for short money in a drugstore in any town where you might happen to be. Mouthpiece cushions, not so much. If the bus rolls into EBE, Nebraska with half an hour before the show, you can probably take that roll of tape out of your bag and wrap the mouthpiece, or run to the local drug store and lay a buck on them.