A few of the sculptors are still with UM I believe, unless they let those guys go when they nearly croaked and decided to completely redesign the Void line. But, in this particular case, it's John Grant that the website is registered to.
As for the value of the items though, you're right Gubs, it's not worth the legal fees. But, a nice cease and desist letter demanding the return of their property doesn't cost much. And, it usually does a fairly decent job of letting scumbags know that the appropriate parties are on to them.
Of course, adding such artwork to the assets Paradox is now seeking to license may just sweeten the deal a bit. Perhaps it's just because I'm a fanboy, but as a wishful licensee, I'd kill to be able to introduce those pics into the next version of the game.