Apart from the mentioned absence of black PVD on the visible metal parts (CG pin, tube, crown), and the frame of the date window, which does not look difficult, but does not lend itself to either TTF or SBF, I suggest paying attention to the sub-dial, which, has a concentric and glossy , as on classic submersibles (and not only), while it should be matte and have a texture that fully corresponds to the overall texture of the dial.
Let me remind you, exactly the same problem that we saw on PAM616 V1-2, and fixed on V3. Although models such as PAM508 did not have such problems initially.
I am attaching GEN photos for reference: