Lost Frost/Nixon material found in a presidential archive

It is fascinating to learn that 'lost' recordings of the famous David Frost/Richard Nixon interviews have been discovered in a US presidential archive.
The broadcast interviews were considered political dynamite when they first went out on The David Frost Show in 1977
They included the first apology from the US President for the Watergate scandal and sealed Frost’s reputation as brilliant interviewer at the pinnacle of his career.
David Frost, who was later knighted, enjoyed a mighty and varied career and for many years was closely involved with Clive Conway Productions.  Sadly he died in 2013 and for a while it was thought that many recordings of his TV programmes, that had been wiped, were lost.
But now Frost’s son, Wilfred, has located dozens of forgotten tapes of the show including the Nixon interviews.
It seems the programmes were recorded on a special equipment by White House Staff who liked to keep an eye on people they considered of interest politically.
The Frost/Nixon encounter went out in three 90 minute programmes watched by millions.