I don't want to reveal all my secrets regarding the tube, but I can reveal the obvious ones. I spent first 2 years just researching and testing many different technologies to make such a small tube with 4 digits, and another 2 years perfecting the technologies I chose.
I use kovar (cobalt nickel and iron alloy) headers with glass feedthroughs for my electrical connections (these are used in military / space technologies and in microwave circuits). Those are very durable and leak proof. They will not leak to spoil the noble gas inside, in 100 years.
For windowed lid, I use the same technology but instead of feedthroughs the whole window is sealed in the kovar frame. Very few companies in the world make those, especially large windows like mine. These technologies are meant for lasers and such stuff where openings are much smaller, so it is expensive.
I have developed additional features for vacuuming, gas and mercury dosing and activating the getter inside without RF power, but I can't reveal all specific procedures.
The construction inside is made of stainless steal and zirconia layers with some PVD coating on some parts.
Lid and header are laser welded together and the whole tube is tested and proven to be leak proof below 10^(-12) mBar l/s. That is the minimum my equipment can measure.
Small run or big run, the process is the same.
Is my answer good enough? ;)