I got tired of hand cleaning the corner protectors using steel wool.
I decided to use a steel wheel on the two rear ones.
This is after the cleaning.
It's a little bit more shiny than the fronts (there's a little bit of patina left but not as much as on the fronts).
This is the power wheel that I used.
The right side is a coarse steel wire wheel.
It's an old grinder and after I cleaned the corners, it stopped working. A little bit of acrid smoke too...
Will take it apart one of these days to see what happened inside.
It may be toast...
Installed the left rear one...
And the right rear... Done.
Decided to not do the bottom corner protectors for now.
When I either fix the grinder or get another one, I'll use the steel wire wheel to do the bottom corner protectors...