Hi,
I don't know how finished your brass hardware is to start with, but use files to remove the flashing and rough surface. Assuming sandpaper may be the only abrasive available to you, start with 80 grit wet or dry paper. Dip the paper in water as you go. Then do the same with 120, 240, and 400 grits. Rather than using finer grit paper from there, I suggest maroon and grey Scotch-Brite pads, again dipped in water. It will go much faster and you will do a better job, if you use water. Finally, you can burnish the surfaces pretty well with a vigorous rubbing with 0000 steel wool.
dave