Grease or oil will wipe off with solvent, finger prints on polished aluminium will oxidise the surface (as will air, but the acids in skin secretions accelerate it), so they would need to be polished off, and matching the sheen of the factory polishing will be a PITA.
Grease or oil will wipe off with solvent, finger prints on polished aluminium will oxidise the surface (as will air, but the acids in skin secretions accelerate it), so they would need to be polished off, and matching the sheen of the factory polishing will be a PITA.