Okay -- so it needs to be the same diameter as the FREEWHEEL threads, and then the freewheel sandwiches it between it and that step up in the hub flange? Okay -- that makes sense.

I don't have anything at the moment. All I'm seeing online are chrome repops. I've been looking for an aluminum one -- not so much for the weight, but for the slightly duller finish. It seems that nobody repops the aluminum ones...

Thanks for the explanation!