I put a MS9 with a Toshiba tube in my Neo 29 that originally came with a Hitachi GMK-29FS2. I had to replace the video input connector and make a new harness for the manual degauss. I also 3D printed some mounting bushes, but that isn't something that has to be done necessarily.
Anyway, works great, looks great. The curvier Tosh actually seems to match the bezel better than the Hitachi.