So far these buttons have not been repro'ed. A google search on RGVAC will turn up some hits from some guys who investigated this, but the tooling setup costs quoted by Cherry ($10,000+, I think?) pretty much ended that idea.
Your best bet is to scour eBay for just the buttons or Atari control panels that still have the buttons intact. Some people have found local arcade op's that still have the buttons on the shelf, but when they are gone, they are gone.
