Tim,
I recently had a similar venture where I was given a bottle of Bailey's that
was about 8-10 years old from my parents that they had lying around. It was
unopened and in original festive tin. However since it does contain cream I
ended up tossing it. They say that you should consume the liquers that have
cream in them within a year of purchase. I am not sure if it is different for
what you have but I doubt it. I was able to score a bottle of absolut,
johnnie walker and Chivas Regal while I was there that was also that old and
had no affect on them whatsoever.