Can uou determine year bottled and worth of a bottle of chivas regal?

12 year old chivas regal. original seal. was my mothers who had it for many years and died 19 years ago.|||If it still has the tax seal it should have a date. Whisky does not improve with age once bottled however so it is only worth whatever a bottle currently is selling for.|||Chivas is a blend. There's nothing special about it, so it won't "raise in value" over time.