The PC in a thin case would be the goal to achieve, hence using the 240, as they perfectly do with the 5140/5940 etc... (I would not like it in a 5980 case personally)
Now, I wonder how round subdials would look in the Nautilus case? Or maybe they can use the layout available in the 5213 you mention (or 5159, 5496 etc...) The thing is that the 5159, 5496 (with retrograde date hand) use the 324 caliber, thus the thicker one... I don't think they can adjust it so easily on the 240.
Otherwise, I read the rest of your thoughts with great interest and I follow you completely!
Another point: waterproof. The 5712 is 60m (whereas all the others are 120m). I heard from Patek it was because of the thinness needed in the 240, thus the gasket where also smaller. Maybe it won't be 120m anymore...
We'll see at Basel or later in the year.
Cheers, Mark



