Multiple auctions have been found with discs identical to the original release. Perhaps they repackaged unsold discs first, before pressing proper Platinum discs. This seems to have been the case with several European Platinum editions of the game.
3. Front of manual
4. Platinum disc
5. Regular disc
Thanks to eBay members flash-game (images 1-2), christof7583 (images 3-4), and retro_story (image 5).