This might be what you're after. This top case looks to be generic design so the rack should fit yours and my RJays casehttp://www.ebay.co.uk/itm/GIVI-E460-E360-TOP-BOX-CASE-METALLIC-LUGGAGE-RACK-E81-GHOSTBIKES-/400494716751
Chrome would have been nice..... Accent the black bike Streak...
I know you'll have thought of this.... But make sure you seal the the holes (weather proof)