They're up on TEKKEN NET (it's the online system the arcade machines are constantly connected to)
Wow, these are awesome! What's the source for these? I want to make sure I get the entire collection.
Namco was holding up a little lottery draw game thing on the site for members to play, it was a simple card flip game where you get the chance to win in game gold or these illustrations.
That list I posted was all the illustrations people have won so far and shared online. (mostly on Japanese boards)
If I find some of the last few I'll post them up here or at the Tekken OT.