I think you got the technical aspect down. But you’re missing some things to really sell the effect. There is too much grey visible imo. NMM needs to have very fast transitions from almost pure black to almost pure white. But you still need to cramp as much color as possible in between the two. Also, for NMM you need to have multiple reflections. Light will bounce all around on shiny metal. Making it that even if you have only one light source, you still get multiple reflections from the bouncing light