Re: crown royal 1948
I'd say open it. While it's surely worth a premium above today's Crown Royal price, the elevation of such premium is reduced by the industrial-sized production of the bottlings. In other words, there is almost NO Crown Royal that is truly rare unless you go WAAAYYYY back in time. Also, it hasn't changed that much over the years, taste-wise, so a 1948 might not be any more interesting than a 1964 (which I happen to have finished recently, to great disappointment).
Still, the difference between 'old' and 'modern' bottlings is recognizable and interesting but only, of course, if you have an 'old' bottle such as yours for comparison.
In any case, it's not going to make you rich. Feel better?