Quoted from ts4z:I need to get up the patience to figure out what to do with the mounting rails, as they have a fair amount of surface rust.
Soak the rusty/tarnished bits overnight in EvapoRust - that'll take care of 90% of it. Then put them thru a tumbler (if they're small enough) or hit it with a buffing wheel (if too big to fit in a tumbler).