Alright, so I put together a cover. I'm not sure it would pass quality control on the site, but I'm happy with it for my own collection. I adjusted it to fit some of the North American style (Nintendo logo at the bottom left and on the spine). I removed some of the Japan-only markings.
The dimensions of the back are a bit odd, but I don't really have another solution in this case.
This required a fairly extensive amount of Photoshop work. I left some of the work up to the content-aware tools (most notably the gray background). The original image had a price sticker over a portion of the image on the front. I rebuilt that portion of the case using a low res image on Wikipedia and some meticulous clone-stamp work. I'm actually rather happy with the rebuilt image.
I've got the full cover uploaded to MediaFire here:
http://www.mediafire.com/view/lm3st5mardeht3b/X-Ekkusu-final.pngAnd, of course, the pretty preview:
