I grabbed the 7 speed cassette and drilled the rivets out. Unstacked, this is how the pieces look. This means I can mix and match them! Since I am using a 28 tooth and a 14T, I only need those two and the small one that interlocks with the lockring. So I measured the stack of the others and made a spacer from some PVC pipe. I also made a spacer to hold the bearing in place. I added some bearing balls and a cone, and slapped it together.
The result is below:
Yay! Taps and dies are strangely satisfying for me.
I'm very close to having this thing ready for welding. I think I have a pretty good road map right now for FINISHING this machine.