Simon needs to chime in on this because he researched this extensively, but from what I understand it is not a straightforward transplant of the 2892 Soprod movement into any other case. There is some milling of the case needed. I notice that the Power Reserve cases I have (027 & 028) are deeper or the caseback sits lower (which may mean just a deeper caseback) that a normal case.
I would love to know because I could just start with a fresh Polished case to make the PVD process less costly. As it stands now, since this latest batch of 028's are a PVD coating on a brushed case, there are multiple steps required to get a new PVD coating Right. The case needs to be blasted to remove the existing coating. Polished to accept the new bead blasting and then PVD coated.