Unopened Republican Decanter 1970's

This item was given to my husband by his grandfather. The label on the front of the decanter says "BEAM 100 months old Kentucky Straight Buorbon Whiskey Bottles b y James B. Beam Distilling Co. Clermont.Beam, Kentucky. " As you can see by the fourth picture, it has never been opened. We would just like to know what it might be worth. Thanks!!