Yes, you are correct.
Despite Patek's website currently only showing the grey dial version, the 4910/10A does come in all three dial colors. The black dial version can be seen in their Twenty~4 microsite.
Thank you for reassuring me.
I've thought about this myself and could not find a good way to drill from the inside. I think a milling machine from the outside would work well but I believe Joe uses a jeweler's drill press and drills from the outside.