Error!
I thought the link you put up was the same trader, I was wrong however.
Looking at my feedback from ages ago I found the trader was infact "Desmo-Porsche"
Here is the link to his Dzus fasters for the Aprilia Factory. (Cost Me $28.00 + $8.00 Postage (£18.71 at the time))
Link
The Dzus he sent me were genuine, the clips have DZUS stamped on them, although the actual fasteners dont.
The quality was good I thought, after 2 years of cleaning they still appear black, however around the edge of the fastener there is a sort of shine developing, but unless you look from about 6 inches you would not notice.
I would recomend this supplier and would use him again simply because what he supplied was good first time round. I seem to remember I got them really quickly too, which is good since they were shipped from the US.
My Dzus are exactly the same measurements as those shown on the link.
Hope that helps.
PS.
If you want me to take a close up digi photo of the fastener as it is today when I get home, I will.
PPS.
Just found the website for the tech details of Dzus fastners
HERE (Warning-Technical, but you can order custom fastners though)
The website is called southco, the DZUS (Panex) fastner designer is
HERE