Campagnolo Record rear derailleur tuning

I took some time to sand the rear derailleur. There are logos to remove in 2 areas, and I wanted a stealthy, all-black look on my derailleur without these logos.

Original weight: 185.0g. Note the Campy Record logo.

Campagnolo 10-speed logo.

Now, to the tuning details...

After very rough sanding with a half-round file.

It doesn't look too good after sanding sometimes. I have to let you know that. I don't know why, frankly. I suspect it's one of the grits of sandpaper producing the whitened appearance. I get patches of that on other parts I've sanded. Again, I suspect one of the grits of sandpaper because sometimes I don't work on the entire surface with a single grit of sandpaper, so the inconsistencies can be attributed to that missing grit of sanding. There's no damage to the cosmetic layer, because it looks completely normal when you rinse it. Then again, I have still yet to sand this with the 600/1500 grit paper. I think I will choose to clear-coat this piece, since I'm planning to repaint the silver body as well.

Half-completed sanding process.

The next thing I'll do is to change the bolts on the derailleur. They feel pretty light actually, I believe they're titanium bolts. Nonetheless, I'll replace them with aluminium bolts.

Cable clasp bolt: 1.5g

Tensioning bolt and spring: 4.0g

Limiter screws and springs: 2.8g

Limiter springs: 0.3g (implying that the screws weigh 2.5g)

Total weight of bolts to be replaced

Now... 7.9g might get cut down to around 4.0g. That's 181.0g (the sanding does reduce weight, but I expect to increase it back when I've repainted it). I also plan to replace the derailleur mounting screw, the steel pulley cage (one of the cages is already carbon fiber and won't be lightened with a new pulley cage), and the 2 pulleys. At this rate, 160~170g sounds reasonable... But where's all the additional weight?! I need to reduce this to 110g.

We'll see.