I would suggest you just try to match the finish of the rest of your watch, the gen finish is finer than that of the replicas, and it would look strange if your bezel has a finer finish than the rest of your watch. A full rebrushing of the Nautilus sounds like quite a bit of work, at the very least, one would need to disassemble the watch head in order to rebrush the part of the case below the bezel correctly.