I have a Calvert Reserve whisky bottle that I know almost nothing about.
It has an intact South Dakota 15c alcoholic liquor stamp, but I have not found any information on the internet about that either.
The bottle's markings are on its bottom. They are circled by the 'Federal law forbids...' statement and are arranged like this:
67 | 56
Any information on the bottle or the stamp would be greatly appreciated.