Older Crown Royal Bottles

[McLeod]

I'm new to the forum and now, also new to collecting.
My father passed away, back in Dec/15, and while cleaning out his home, found several open and unopened liquor bottles. ( he always entertained large parties and always had open bars ) So some bottles, I have boxed away and may post at a later date, as these are older bottles unopened as well.
My question is, with several Crown Royal bottles unopened, as the years go by, does the whisky inside change ( flavor, colour etc ) I only ask, because one bottle is a 1.14L from 1977, 2 are from 1981 and 2 newer bottles with the clear sealed band around neck.
So obviously, I don't want the whisky to spoil, so after 40 years I would like to keep it, as well as the others, unopened if possible.
Greatly appreciate any advice.....