1955-58 Buick Dynaflow - Vacuum-Pitch-Control

I am clearing my father's estate. Most of his fixations were on cars newer than those the Jalopy Journal caters to. I am finding stray parts with older applications, though.

This is something I haven't found a lot of information about. Hoping you have some insight to share.

The box is in terrible shape. If there ever was a part number, the flap which carried it is gone.