What about a solid blocks of this RTM material, then machining the watch case from it? The part that is shown in the images still needs some finishing, I assume. What about a solid rectangular piece, then you machine the case in a 5-axis CNC. That would be far more doable. The only question is durability during construction, metals are predictable under Tungsten Carbide tools, not sure if this CF/epoxy mix is too brittle to be machined...
Other than that, this project is crazy, you're all nuts!
P.S. I's DEFINITELY be up for one, pending surface quality )