Era:  1970s
ABV:  40%
Volume:  68cl

Did you know that Metrication is the term given to the process of introducing the metric system of measurement in place of the imperial system?

If you did know: 10 points.  If you did not know:  0 points.

This bottle dates from the 1970s and the transition is clearly in full swing as indicated by the use of both 24 fl. oz. and 68cl on the label.  In contrast, the old proof system is still in place as the change from, say, 70° to 40% ABV did not occur until 1980.

History lesson over.  Class dismissed.