The show was released officially as part of Deep Purple In Concert, including Peel introductions, along with a second In Concert date from March 1972, introduced by Mike Harding.
On this occasion, the band were apparently a late replacement for Joe Cocker, who is given as appearing on this date in The Peel Sessions. Ken Garner has confirmed this was an oversight probably derived from the Radio Times programme listing. In Session Tonight lists Deep Purple on this date. Many thanks to Ken for clearing up this point.
The available recording sounds like a rip from the album rather than from the radio broadcast.