Not sure perhaps you can enlighten me to the differences. in the interim I have uploaded 2 images of the case to a site (links here):
Note on the cardboard wrap cover how it says "Bonus Metal Case" and not Steelbook. Do steelbooks have that extra flat bit on the spine which covers up the rather ugly hingeing (like in the AC games steelbooks)? I can find no G1 nor G2 etched anywhere into the steel. Is "steelbook" a copyrighted term for the ones I mention?