Designed my own version of the RB rear brace and had it made by the sheetmetal guy that does all our manufacturing at work.
It looks like this fitted:

I did want it in Zinc seal rather than hot gal so I could paint it black, but that was the only #14 gauge he had kicking around the shop on the day. The fit was just about perfect, I had to adjust 2 holes with a file, but this information can be fed back and the programming file adjusted for the next one. And now that the programming is done and paid for, I can get more run off for pretty low cost. It's all punch-and-nibble rather than laser-cut, but it ends up being cheaper per-unit if lacking in pizazz.
Finally got out for a drive last night. Noticeably tighter rear end. Nice.