I'm also considering having some made to replace the Shad (oem) ones before they break. But i like the minimalistic aproach of the fitting points and considering to reuse them.
If i have some strong alu. boxes made there is no need for a big rack when the plastic ones can get bye without. Just having to figure out how to mount them
Here is a guy that stand by (on) his work :-)
If i remember correctly it is 3mm alu and welded all the way