Zipper Repair Tool - Glen Zip Jr. Glenard Tools Vintage

Description

This listing is for a very old zipper repair too.  It is a Glen Zip Jr. made by Glenard Tools of Chicago. Illinois.
It is in the original box.  The box shows a lot of wear as does the tool itself.  It looks to be made of aluminum and has white corrosion on it.  It still seems to work, although I haven't the foggiest idea of HOW it works and what is is actually supposed to do.  I found it in my mother's sewing stuff in my parent's estate.
From my parent's estate.