Congratulations, ray!
The only thing that was a little fiddly about the swap to the emulator was the actual hardware that holds the floppy in the controller... I had to use a few washers to lift the emulator a little bit higher into the opening. It';s not a perfect fit, but I got it so that there are only two very small slits above and below the face of the emulator, and since it's dark inside the closed piano then they are not noticeable.
If someone is really enthusiastic then it would probably be possible to fashion some sort of plate that would fully fill the original floppy opening.
I also used the drawings of the controller in the MX100 service manual (available here in the Files section) to be sure that I correctly oriented the Pin 1 one each cable (floppy data cable and floppy power cable). Incidentally, the original floppy cable is too short to connect the emulator properly. I got a replacement floppy cable from MicroCenter, and that did the trick just fine. Here is a link to a cable which is similar to mine that you can order from Amazon:
Best of luck to you, and I hope you enjoy using the floppy emulator!
Scott