curious if anyone can help me decipher the riddle that is this glass jar. Thanks!
According to the Brockway Wikipedia page, the company was around until 1987 when it was bought out by Owens-Illionois, the present-day multi-national monster glass company which grew at least in part by purchasing smaller firms.
Your jar dates to the later years of the company as evidenced by the dotted texture around the edge of the base.
Many people think there is some Little Orphan Annie magic decoder ring which can reveal the meaning of the numbers, letters and symbols on the bottom of 20th century bottles and jars. Unfortunately for us bottle hounds, this is all propriatary to the individual companies.