Amazon.com: Disc Brake Rotor, 5 on 4-1/2 Inch, 2 PK, Fits Mustang II : Everything Else
Amazon.co.jp: WildCat Rotor Bit Plate Bit (90° x 5mm/5 Piece Set) Electrodeposited Diamond Bit, Triangle Head, Mini Router Bit (Recommended as a Processing Tool that Require Fine Adjustment of Mini 4WD) :