Congratulations on the new acquisition.
If memory serves, the MBW bezels do not readily accept gen inserts (at least, not the 2 I tried) without modification, which is why I ended up installing a gen insert & bezel. The best options for the MBW bezel are to install a PMWF insert & Ofrei illumines dot (pearl). As far as I can tell, these are the same parts that Rolex installs, currently, during servicing (if replacements are required).
If you are critical, I would highly encourage you to do some research on gen double-reds before you pick up a file or shell out any modding cash. There are many online sources for great info, but this is probably the easiest place to start.