Gen 15202 have had historically monoblock midcase & caseback, i.e. made from a single piece of steel. My understanding is that AP changed their architecture as of late and they now produce 15202s with a detachable caseback. How that affects the screws construction is unknown to me. I believe the monoblock model has a similar screws solution unlike the 39 and 41mm ROC where the bezel screws are faux. Given the rarity of 15202s it’s hard for me to be conclusive but that’s what I’ve seen in the past.
Other than that, you are right that the gen 15202 should have a rubber movement holder that doubles as a gasket.
Yes, the RO 5402, 14802, 15002 and 15202 (14790 as well) came with monoblock case. This changed between 2015 - 2016 where they switched to a non monobloc case. Screw construction on the case design from 2016 is most likely the same as the 15450, 15400, 15500. Before the design was the same as the previous versions. I'm not sure what you mean with faux bezel screws buddy as they all have a thread and can be screwed on to from the caseback side.
Whether an RO has the newes case or not can be determined by the caseback. Monoblock says "Royal Oak" on top, while the non-monoblock says the N°.
I series = monobloc
J series = new case design/non monobloc
AP won't mention why they changed it. Most likely for service I think. "Regarding your inquiry, please be informed that there is a modification done on the case for the model 15202ST, it used to be a monobloc and it is now a 2 pieces for the case and back case. We are unable to reply to you on the reason changed as this is a private information that Audemars Piguet will not divulge."
