The unseen Star Wars archive footage used in Rogue One
Director Gareth Edwards keeps on top of his recycling
possible spoiler alert
OK while the CGI Tarkin was a bit odd, one of the most impressive feats was how Rogue One digitally resurrected Garven Dreis and Jon Vander (the Red and Gold Leaders from A New Hope).
It turnes out that it started by accident. Edwards said that he stumbled across some never used footage while hanging out at Skywalker Ranch while researching for Rogue One. He found original negatives from A New Hope with deleted scenes of the pilots. There was even an X-Wing call sign exchange that didn’t make it into A New Hope. So they digitally cut around the footage of the pilots and inserted the characters into the cockpits used in Rogue One.