I would love an All American!!! That's on my list too. I've not had to replace any of the gaskets on our presto model but the gauge has had to be replaced. I've learned that I should not store them in the cold garage in winter.
That is surely a good knife if it's served you so well for 45 years - I love that. I wish things were made to last like that these days.
I am always so careful to look for those things that will because it really is upsetting when money gets wasted!
To keep the gasket from oxydizing, I sealed it in a vacuum sealer bag with oxygen packs... Did the same with the rubber rings for bale type canning jars.
oh that's an interesting idea, thanks for sharing!