At Amiwest 2013, Beth Richard, the developer of the CD 1200 gave a talk about it. She said that 9 prototypes were built. It had an Akiko, RAM socket and an FPGA that convinced the Akiko that it was connected to a CD32 on the board that connected to the 1200's expansion slot with a cable going out to the CD drive. She said it was 100% compatible with CD32 software.
There was a 2nd version planned as something to entice a possible buyer of Commodore but that fell through so the 2nd version was never built. It was planned to replace the Akiko and FPGA with an ASIC and add a 68030 socket.
You can see her whole talk at
https://youtu.be/eOJ7XVQlnB8The part about the CD 1200 starts just past 49 minutes.
Richard was involved with the whole line of multimedia products including unreleased ones like the 4000 FMV card which was the basis for the CD32's FMV card. The title of the talk was "The Development of the FMV Card". She covers the whole history of the multimedia products including lots of architecture and theory, why some decisions were made.
It's less than an hour and well worth watching.
