Update: Got a second Carrera CV2A10 case with black bezel today from a great member over on RWI. It came complete, minus the crystal, which is perfect for what I wanted to check.
I can now confirm that the black bezel 43mm Carrera is a different construction than that of the chromed bezel 43mm Carrera.
The black bezel insert came out very easily, and is held in place with double sided thin sticky tape, and not snapped into position.
Quite happy with this result, as now I know I can go ahead and replace the black insert on my franken with a genuine insert, although I will bond into place with either Hydro Cement of Gorilla Glue. I have confirmed dimensions from my genuine parts supplier of both the crystal, and bezel insert, and its good to go, so will be getting these gen parts soon.
Seeing as the Gen case set is a little over $1k, I have enquired about getting just a gen case back.
Both the first Carrera donor case, and this second one, even though both are stated on their case backs as CV2A10 Carrera models, I have to say, they looks very slightly different to my franken case. More noticeable in the lug areas, but very minor.
On the donor cases, the lug profile is shorter, and not as wide as my franken. I will add photos showing this difference, and also some measurements once my digital calliper is fixed as I broke my lcd.
Hope the above info is of some help to you should you be wanting to carry out any similar mods to your Carrera
Thanks for reading, photos, and measurements to follow in the next update.