To sum it up, likely a Tungsten rotor, gold bezel, and gold capped bracelet links. 316L steel cubic density is 8g/cc, 18k gold is around 16g/cc/, and tungsten is just over 19g/cc.
The rotor is probably ~0.4cc, so a tungsten one would increase the weight by ~4.5g
The bracelet has 15-16 links that are gold capped. Gold caps are usually ~200 microns (0.2mm) thick. Each link is around 2cm of area, which is around 0.64cc altogether, so the gold capped bracelet adds another ~5g
The bezel is probably another ~0.5cc, so a gold bezel would add another ~4g
Altogether 13.5g increase. Not too shabby.