Anyone replace one of these? I've looked here and on the internet as to where to get a replacement for mine with no luck. I have the drive shaft off to replace the U joints and remove the 60 years of accumulated crapola. Unscrewing the retainer I noticed mine is in none too great shape. It LOOKS to be cork, looking at the 1955 Online Chebbie shop manual, page 4-65, Fig 111 it points to what they label a felt packing and below in print they call out cork??

Any direction is appreciated.