Same wing head thumbscrew is available from these guys: http://www.metricmcc.com
but you've got to buy 25 pcs. minimum at $1.11 Each.
The wing head thumb screws are not as elegant looking as the OEM Ducati slotted/knurled units, but they're not in plain view either. Additionally, you can get 'em way tighter than the thumbscrews, and you don't need a tool (even if it is just a quarter).
Conceptually, they are a lot prettier than the empty hole left by a departed OEM part, and way better looking than your seat cowl after it's been pressed flat by a semi.