While I agree with most of what Peter Copeland says below, I sadly must
disagree with his assumption that "Future restoration processes should
inevitably be better than present-day ones."
I am on a number of technical commissions that are involved in writing
preservation standards dealing with magnetic tape and, having passed my 50th
birthday, I am the youngest active member on these commissions. To me, the
greatest danger we face in the preservation of much of our recorded material
is the rapid obsolescence of qualified technical personnel.