Guess the Snap On Tool?

[bigcaddy]

This little oddity followed me home this morning with an decent sized handful of snap on tools and other assorted garage items. I don't even think I tried to pick it up but rather it was at the bottom of a box I found with other tools I wanted

Anybody have an idea as to what it is? The internet couldn't provide a shred of info

Date code reads 1955

 

[Hiball]

Carb tool/gauge I believe.

 

[jethro29]

pretty sure the mc is for motorcycle but other than that I'm lost.

 

[GTA Matt]

Its for setting the float level on a carter 1 barrel carb

 

[joel63]

Its for setting the float level on a carter 1 barrel carb

This ^^^
http://www.collectingsnapon.com/catalogs/catalogs-large/1955_Catalog_V/1955-Catalog-V-p016.jpg