Not a clue !

[Sudsy]

Came out of a home machinists shop. Looks like it fits in a drill

7" long

Reads -

             7/16

             B&D

       United States

         Of America

[wvtools]

As luck would have it I found it in the first Black and Decker catalog I looked in on the first page I looked at.

1946

Under Carbon Cleaning Tools

Valve Guide Cleaner

Looks like it may be the 21449  7/16 to 31/64 inch

Made of spring wire set spirally about a stem and expanded to give heavy cleaning tension.  A few strokes with this cleaner driven by a 1/4 inch drill thoroughly cleans and polishes the valve guide.