At the risk of getting my hand slapped for being OT, I will relate
something to you.

Several years ago in Kansas City  I went to the display of the artifacts
found on the Steamship Arabia which sank in the Missouri River in 1857
and was found about ten years ago.  Among those artifacts were some
Disston saws.

A restorer was working behind a glass window removing rust from one of
the tools using a draftsman's electric eraser. I had a conversation with
him about it.

I priced electric erasers and decided I could live without one. Until I
accidentally ran across one on eBay and bought it for $26 with three
boxes of erasers.

This is a very effective tool for removing rust.  Erasers are 7 inches
long and fit inside the tool. They are available is numerous different
grits. This is a slow but sure way to remove rust without harming the
tool.  One more way to restore.  

Jim Thompson