http://www.motocorse.com/news/accessori/17818_TopSellerie_-_Selle_personalizzate.php (http://www.motocorse.com/news/accessori/17818_TopSellerie_-_Selle_personalizzate.php)
I think this is a French company. I can't find out where to order, but thought you all might want to see, since Corbin is so hard to get.
(http://www.motocorse.com/foto/17818/thumbs500/1.jpg)
Here you go: http://www.topsellerie.com/@EN-FR/saddles-petrol-tank-covers-tank-bags-leg-handgrip-covers-motorbike-scooter.html
You can design your own seat or just a cover. They don't have all model Ducs listed though. May have to contact them if yours isn't listed. Mine wasn't. Apparently you can even add gel seat cushion and heated seats if you want but the price starts to show.