Does anyone have a source for replacement crown seals for the Autavia 1163 and similar. I get a lot of requests to replace this now, especially the ones that have turned to "goop". I looked at some of my other new unsigned WP crowns but they did not a similar type of seal. Removing the retainer washer off the back is tough on these so any suggestions on the best way to do this would also be appreciated. Thanks, Craig