Well, here's what I do and it's NOT foolproof. I Google it. I Google it in Web and in Images. IF it is legit, it may well have been blogged about.
When I Googled "Kooba Sienna Special Edition" I got this from Kooba's site:
http://shop.kooba.com/Sienna/pd/np/119/p/96551.html
It's not what you're considering bidding on.
I also found a blog entry about someone who won a cream colored Sienna Special Edition in a handbag contest. She notes the lining is lavender. There's no mention of gold stitching. It's a 2006 blog entry.
Now, that doesn't mean Kooba didn't do gold stitching. It doesn't "feel" right to me but I can't discount it. Kooba has done printed linings but long ago, and all the printed linings I've seen had fabric interior logo tags, not the metal plates. And all had the metal zipper pull.
But go play on Google. You might have better luck in matching it to something.