How old is this, and is it worth anything

For context this is a 90 proof bottle of heaven hill my grandpa use to own that my dad gave to me along with 5 other older whiskey/burbon for my 21st. I dont know anything about them and neither of us drink bourbon/whiskey so Im planning on selling them but I dont know how old they are or there value or where to sell them. I have tried looking this stuff up online but have gotten mixed results. Any advice or knowledge is appreciated.