Very interesting...
As for spare RB engines, that may be far from "production." I just got my hands on it yesterday, but I intend to find a way to "copy" it. A long time ago, I used to "clone" parts of action figure toys, but I have yet to see if the quality of the substance I used is up to par. If it isn't, I will start experimenting with resins and epoxies, perhaps even cyanoacrylate.
I'm going to start by making rubber molds of the parts. Finding the appropriate material to cast them in after that is the hard part...
Not quite the answer you expected, is it?
How'd you end up with another S2000 already, anyways?