Not much has changed in procedures since your day. You gave a precise account of what should happen and most often does happen, in the world of security. Sandy Berger and the National Archives gave us an example of what shouldn't and usually doesn't happen.
The story that hasn't been reported (and won't be) is that NA staff knowingly let Berger remove classified docs from the building and did so more than once. This is the power of the overwhelmingly liberal federal employees' union.