Use Old Save is an extra from LEGO Star Wars II: The Original Trilogy that adds prequel trilogy characters you unlocked in your LEGO Star Wars: The Video Game save file to the character grid in Free Play. However, it doesn't unlock R2-D2, C-3PO, Yoda, Chewbacca, Darth Vader, Stormtrooper, Gonk Droid , The Emperor, Rebel Trooper or Princess Leia as they are already in the game and needs to be unlocked.