The front rims appear to be Ultra-5/Speedsteer front rims. Ultra 5 rims are usually chromed. They work on the Original Aurora AFX G+ chassis too. I think the machined middle gear came in the original AFX Performance Parts kit or the Super-traction cars. I have a few those that came on the Super-traction cars I've bought, but they may not be original to those chassis.
I also think that some Tuff Ones Chassis also came with those Lightened "hallowed" Idler gears as well. Several of my original Tuffies have them. And I think some Aurora Tuffies may also have come with Plastic idler gears as well ?.