I've got the mounting bars from my Givi rear rack (526f if I remember correctly) that were on my bike when I crashed. They're bent beyond what would be usable as is.
Anyway before I toss em out, I thought I'd see if anybody wanted 'em to try to copy em or fab up something.
If you want 'em, they're yours for the cost of shipping.
(https://lh6.googleusercontent.com/_OYZS1ssXWZA/TXwqaJD9ChI/AAAAAAAAAeg/O8g7UnQaLcw/bars.JPG)