Currently we have to routinely refer to the microfiche and microfilm records. Our microfilm has 270 pages of records per slide. A machine to photo these is relatively inexpensive. By taking snapshots of whole pages, a specialist could easily navigate through the years and records and save a ton of time.
Setting up the file structure would be easy, as the labels would match the years and organized structure already in place.
My thought on security is to have the files accessible via a local computer, not on a network. After all, presently a person needs the physical medium in hand, and it would not be any more inconvenient that leaving the desk.