This came about at my end because, or thanks to the circumstance that, I saw some video, perhaps on Youtube, and perhaps it was about this very same phenomenon with Conner seals, I wasn't sure when I was typing yesterday. I definitely want to keep that Conner going, at least until I get it back into a Mac and see what software (mostly software pre-1992) I have on it, and not yet on some Mac HFS CD. Isn't that great, if I had been here a year ago I think there would not have been your video online, and forewarned is forearmed.
I would like to ascertain what is the best option in synthetic modern polymer sheet material to cut out a new template of the seal / gasket.