National Security Archive's complete index of NSA internal Cryptolog periodical
nsarchive.gwu.edu
nsarchive.gwu.edu
I can't believe there is much government secret stuff from 50 years ago that it's still in the public interest to keep secret today.
They've got something more important to do... their job.
So if you can't have enough time / attention from the person who actually knows, I'm more comfortable with a policy of over- rather than under-redaction.