I need to find out what Electrical thread pitch it is and you can just buy the Jewel & nut.
I've looked at Fibre washers & rubber O rings but they didn't meet my standards!
You could also use kneaded epoxy, I found this stuff is really good for plugging up holes & chip outs!
You just slice a piece off & squeeze it between your fingers to mix the 2 different colours together.
The downside is you can't remove the Jewel as it sets like concrete!!!
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