Wow, am I understanding correctly that you replaced the tube the hands mount onto the pinion with?
Yes, that is exactly what was done.
The gen AP hands have shorter tubes and their tubes are .1mm thinner in diameter, so they cannot be fitted onto the usual ETA models people often install to upgrade their replica Divers. There are other approaches to this modification of course, which I have done in the past as well.
Of course, the replacement tubes are .1mm wider in diameter and have a basic circular geometry which some might take issue with, but the owner was willing to accept that in exchange for gaining the better finish on the rest of the hand set.
BTW, I would just like to point out, the lume on these gen Diver hand sets is surprisingly weak, which is another step back from the replica quality.
As so often, modifications at this level of detail and complication are usually never a complete step forward.
Total work hours for me: 6 hours, but the sound of the tubes perfectly snapping into place on the gen hands once everything was prepared, was priceless, and something that perhaps only a person like me could take such satisfaction in.