OK, so I'll try and hunt down some Maas, if not that then Mother's Mag & Aluminum Polish. I'll remove as much as I can with a single edge razor then work with some 0000 steel wool. I'm not familiar with fine grit metal sandpaper, are you referring to just a wet/dry sandpaper? If so, what grit? I have NO experience with cleaning metal surfaces so I have no clue which grit to start with.