I have a bottle of Langs Old Scotch Whisky, it has a volume of 4,54 litres and a Britisch customs certificate of origin no. 4, rotation no. 73/202, dated 18/7/73. It is blended and bottled by Lang Brothers Ltd. Distillers are Glengoyne Scotland. It was exclusively imported by Cusenier S.A (Brussels). I would greatly appreciate any information regarding history & valuation.