The British steelbook edition came with a plastic slipcover over the steelbook. It came with a card with DLC-codes and a sheet with technical and warranty information.
1. Front of steelbook inside plastic slipcover
2. Back of steelbook inside plastic slipcover
3. Inside
4. Disc
5. Info sheet
Thanks to eBay members rezir (images 1-2) and alaar66 (images 3-5).