To go in a different direction with this thread: I worked on my 44mm FC yesterday.
Goal was to insert retaining nuts on the 4 bezels screws that do not have them: the ones at 2, 4, 8 and 10 o'clock.
Some modders are gluing these screws in to keep them from falling out: this is an unacceptable solution for me since the glue fumes destroy the dial & movement and the glue makes the watch partially disassemblable.
I got to look inside, look closer with loupe, and handle the hardware.
With FC it is possible to insert retaining nuts on those 4 screws, but you need to deepen the hole for those nuts from the backside a good 2.5mm deeper (likewise on the 44mm Panda but there you have to drill out metal rather than FC). If you do not deepen the hole, the retaining nut will block the case back end nuts from fastening fully onto the bezel screws.
I deepened the hole with a special circular flat bit the same size as the hole while protecting the inside of the watch, because I knew drilling would throw up a lot of FC particles.
Inspecting the case back end nuts, I saw that the thread for these starts only halfway into the nut, and that the nut opening is a little too wide for the bezel screws.
In fact, 3 of these case back nuts would not thread at all on the bezel screws: I think they were factory assembled with loctite to keep them on to begin with. This means that the case back nuts are in danger of falling off the watch and releasing the bezel screws if the latter are not secured with a mid-case nut.
I started machining replacement nuts for the 3 or 4 nuts that would not thread, but the slots on these were too big, so I reserved them for some other project.
Then I decided I would slightly crimp the 3 original rep case back nuts to reduce the hole diameter. It worked like a charm with only a little crimping. The 3 fit now snugly on the bezel screw.
Then I noticed the bezel screws were not sunken on the bezel. This is because the rubber washers are pretty thick. I replaced these with much smaller washers to allow the screws to settle below the bezel surface.
In the end, now I feel a lot more secure walking around wearing the watch knowing it is mechanically sound.
Inspecting the movement, it was really clean, much cleaner than some of the other ROO movements I work on.
The hardware, esp. the case back is really well designed, and snug. My esteem for the 44mms improved as I worked on it. This is a nice piece of work.