Great idea! I have been wanting to buy a set of nut files, but don't have the money to spend.
I do, however, have a huge set of various sized files (inch, metric and letter designations).
I like the idea of using emery cloth, too.
We also need to adjust for the thickness of the emery cloth/sand paper, for the overall size.
-New York Bassists Club #68
*Rockin' Carlo Robelli basses since 2006!*