Re: Crown Royal seal intact 1956 unopened - looking for valu
It's probably best to coduct a cursory check on the internet on sites such as ebay, etc. I wouldn't expect too much in the way of financial reward compared to present-day prices for CR, however, as such venerable bottles seem to be just about everywhere. Plus there's always the lurking question as to the state of the contents. I'd imagine a fair number of these sorts of whiskies have spent years tucked away under less than ideal conditions (though that may not be the case with your's).
If I were you, I'd simply consider opening the bottle and tasting the whisky. Crown Royal editions from that era usually contain blends of older whiskies (from around a decade of age up to three decades), as well as being comprised of spirits distilled at a number of Seagram sites (like the renowned Waterloo facility) operational at the time. As such, they provide an opportunity to peek into the past.