It looks like that part is sold only as an "assembly" with the mirror.
Not sure which part of the assembly you need. There are lots of mirror adapters on ebay.
Used LIKE mirrors (200i or the 50 cc versions - it's the same mirror) , eBay?, may be your best bet.
Or, try a shop like Fastenal that specializes in strange hardware.
Might be worth a phone call to one of the various on-line Kymco parts scooter shops listed here (General Discussion), maybe they have a loose one to sell.
Stig