Please tell me what this kitchen tool is called and its use, specifically This vintage tool is stamped "Guelon, France." I believe it is some type of zester, but I cannot find an image of it anywhere online, nor any info on it.

Please help me and, if you can, tell me its specific use and possible decade(s) when it was sold. The image I have added here is the tool shown on its side.



The tool is 7" long overall and the diameter of the round head is 1.5".
Looks like a butter curler to me.


  A butter curler is a kitchen tool designed to produce decorative butter shapes for use in food decoration. It can also be used to make chocolate and wax shavings. In typical use, the material to be cut is chilled slightly while the curler is dipped into hot water to ease the cutting.  


Here's an example of a more modern one and the results of using it: