I'm not intending to make a replacement the same as that, am just interested in the steel thickness used for reference.
From experience I would think the compliance is just ISO 9000/TUV or similar, which doesn't have anything to do with the actual product or safety of it, it's just a paper audit system.
I would also be very surprised if they have a successful patent on that as the idea of metal strut supports id commonplace and it's harder to gain an approval for trademark or patent on a specific item if something similar is already in use.
Due to looking for that I've found another failed strut. Andymcit says it failed due to the rubber tearing, which it did, but looking at it the steel under the rubber section does look corroded as well.

91 3.0 sei M. 4852 EXY Black
92 2.1 sed M. 5740 ECZ Sable Phenicien
92 3.0 V6-24. 5713 EXY Black
92 2.1 sd M. 5685 ENT Blue Sideral
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90 2.1sd M. 5049 EJV Mandarin
92 2.1sd A. 5698 EJV Mandarin
94 2.1sd A. 6218 ERT Triton
91 2.0si M. 5187 EWT White