How can I get the valuation of an unopened, unboxed bottle 1970's Remy Martin VSOP fine champagne cognac? Don't know whether to open it and celebrate or drown my sorrows!
Spirits don't age in the bottle. (For example, if you buy a 5-year-old whisky now and keep it for 15 years it will still be a 5-year-old whisky, not a 20-year-old one; it's the time in the cask which matters).
So, unless the bottle you've got happens to be some sort of 'collector's edition', it will be worth exactly what you'd pay for it today in a supermarket. (£35 in Morrison's).