My theory re X-1:
Vatican Secret Archives
The Vatican Secret Archives have been estimated to contain 52 miles (84 km) of shelving,[2] and there are 35,000 volumes in the selective catalogue alone: "Publication of the indexes, in part or as a whole, is forbidden," according to the regulations current in 2005. The Secret Archives support their own photographic and conservation studios... However, the files are not yet available for public review.
http://en.wikipedia.org/wiki/Vatican_Secret_Archives