THX a lot for the input !!I see you're an Aussie, and out of the States where the vendor I'm siting is located. I'm sure you can find it closer and cheaper. But for reference only....
The rectifier is Part 16 on this schematic. The part number is Yamaha's OEM and will be the same from any reputable vendor.
You can probably do an engine search and find it somewhere in the Amazon or Ebay world.
2015 Yamaha YZF-R3 OEM Parts | MotoSport