The stainless vent windows were presenting a problem in that the pivot used to have chrome on it. But the chrome degrades leaving the chrome in a sad flaking state and the brass underneath pitted as well. Yes, the pivot is brass.
While removing the pivot is possible, putting it back is very difficult due to the location of the rivet rollover within the U-channel. I won't discuss options here.
Some outfits will chrome the whole vent -- which is wrong. A repop is available which I heard is all chrome too.
Charles noted that Qual-Krom will plate just the pivot using tape or other media to keep the stainless from being plated. I contacted them and will have them do other pieces as well.
To keep costs down I decided to remove the chrome and the pits in the brass using a Dremel, file and sandpaper. I tried this on a spare vent frame using only yellow painter's tape to shield the frame but was always afraid of going through the tape and creating a difficult to remove gouge in the frame.
I then came upon the idea of using shim stock to get under or very close to the sides of the pivot. The whole idea is have the brass shim stock take any scrape or gouge rather than the frame. Thin shim stock cuts with scissors, bends very easily, yet protects. The shim stock is held in place with tape.
Although few here may want to tackle the vent frame, the idea of using shim stock around any area you need to protect may work for you. It would also work as a shield against weld spatter.