Canadian Mist 1968
Interesting! Would like to see pics of bottle to make an educated value.
But to the History Canadaina Mist which is a blended Whisky and was blended for a U.S. market. It is still made today and in 2009 Won Double Gold in the Sanfrancisco Worlds Spirts Competition. The labels have change over the years and the bottles to some degree how ever the Whisky itself being blended from a recipe should taste the same today as it did in 1968.
If you were to sell it in Canada the going bottle price is what you would get; however in the U.S. market I would expect about the same unless the bottle is from a original run or the label and bottle are farely rare and may fetch w/ content maybe 10% over current label price.
For my 2 cents worth either keep it safe till its 100 years old or with close (appreciating) friends open the old and the new and have a comparrison tasting party.
Either way I hope I have helped in some way. Please post Pics!