When I was researching Theta transports six years ago, the very issue of the discontinued CDM9 came up. That's why I went with the Theta Pearl which at the time used the Pioneer Stable Platter which was still being made then. I think that has since been discontiued as well. I can't be sure though.
Back then I wrote Theta and they said finding mechanisms for the Theta Data Basics would be very difficult if service was required, and that was six years ago, so I imagine it's even tougher today.
You might try and contact them. Ed Deitemeier of Theta was very helpful when I was looking for a transport, but as I said, it was a long time ago and I don't know if he;s still there.
Good luck!