It's great that the BFI are keeping their prints, no doubt in excellent storage conditions. However, although the BFI always tries to get the best print available for their archive, anyone who has seen prints from their archive can tell you they're not always preservation grade (they are often post-release prints). I'd hold out more hope for the Library of Congress copy, which AFAIK is was pristine at the time of archiving (which means faded and discolored now, but not scratched/torn/dirty).