The back is just a scan of the American retail cover. We don't have any scans of the PAL version, so I dunno how exactly I'd do such a thing.
Also, if you wanted to make these fit a PS3 case (which, I assume, is about the same size as a PAL Blu-Ray case), all you need to stretch is the spine. The front and back of a Blu-Ray insert are the same size as a PS3 inserts, the spine is the only thing that changes size.