Any Info would be appreciated

[RenoGuy]

I inherited my Granddad's liquor cabinet which contained 4 seperate boxes containing bottles marked "Justerini & Brooks 20 Years Old Finest Scotch Whiskey". These bottles have cork stoppers w/ glass stoppers included in the box. The back of the bottles have a label with " 26 2/3 Fl. oz. 75 proof" in cursive. My Grandmother estimated the bottles as being circa 1965 or so but she cannot recall when exactly. Any info including value would be appreciated! I have 3 unopened boxes/bottles and one that has been opened/sampled.

http://i257.photobucket.com/albums/hh202/RenoBob/IMG_3127.jpg

http://i257.photobucket.com/albums/hh202/RenoBob/IMG_3132.jpg

http://i257.photobucket.com/albums/hh202/RenoBob/IMG_3130.jpg