Question: In what year was the English actor that starred with David Hemmings and Douglas Wilmer in "Unman, Wittering and Zigo" born?

Context articles: Islands in the Stream (film)
Tony Haygarth
The Brides of Fu Manchu
Follyfoot
Douglas Wilmer
Journey to the Centre of the Earth (album)
Hemdale Film Corporation
Unman, Wittering and Zigo (film)
Squadra antitruffa
David Hemmings Happens

Islands in the Stream is a 1977 American drama film, an adaptation of Ernest Hemingway's novel of the same name.
 The film was directed by Franklin J. Schaffner and starred George C. Scott, Hart Bochner, Claire Bloom, Gilbert Roland, and David Hemmings.
George Anthony David Haygarth (4 February 1945 – 10 March 2017) was an English television, film and theatre actor.
The Brides of Fu Manchu is a 1966 British/German Constantin Film co-production adventure crime film based on the fictional Asian villain Fu Manchu, created by Sax Rohmer.
 It was the second film in a series, and was preceded by "The Face of Fu Manchu". "
The Vengeance of Fu Manchu" followed in 1967, "The Blood of Fu Manchu" in 1968, and "The Castle of Fu Manchu" in 1969.
 It was produced by Harry Alan Towers for Hallam Productions.
 Like the first film, it was directed by Don Sharp, and starred Christopher Lee as Fu Manchu.
 Nigel Green was replaced by Douglas Wilmer as Scotland Yard detective Nayland Smith.
Follyfoot is a children's television series co-produced by the majority-partner British television company Yorkshire Television (for transmission on ITV) and the independent West German company "TV Munich" (for transmission on the ZDF channel).
 It aired in the United Kingdom between 1971 and 1973, repeated for two years after that and again in the late 1980s.
 The series starred Gillian Blake in the lead role.
 Notable people connected with the series were actors Desmond Llewelyn and Arthur English and directors Jack Cardiff, Stephen Frears, Michael Apted and David Hemmings.
Douglas Wilmer (8 January 1920 – 31 March 2016) was an English actor, best known for playing Sherlock Holmes in the 1965 TV series "Sherlock Holmes".
Journey to the Centre of the Earth is the second solo album from the English keyboardist Rick Wakeman, released on 3 May 1974 by A&M Records.
 The album is a live recording of his second of two concerts on 18 January 1974 at the Royal Festival Hall in London.
 With its concept based on Jules Verne's science fiction novel of the same name, the album tells the story of Professor Lidenbrok, his nephew Axel, and their guide Hans, who follow a passage to the Earth's centre originally discovered by Arne Saknussemm, an Icelandic alchemist.
 Wakeman performs with the London Symphony Orchestra, the English Chamber Choir, and a group of hand-picked musicians for his rock band, which later became the English Rock Ensemble.
 Actor David Hemmings narrates the story.
Hemdale Film Corporation, known as Hemdale Communications after 1993, was an independent British-American film production company and distributor founded in London in 1967 as the Hemdale Company by actor David Hemmings and John Daly.
 Hemmings left the company in 1971, and Daly purchased his stock.
 They were known for having produced numerous acclaimed and well-known genre films, often in conjunction with companies such as TriStar and Orion Pictures.
Unman, Wittering and Zigo is a 1971 British thriller film directed by John Mackenzie and starring David Hemmings, Douglas Wilmer and Tony Haygarth.
 It is adapted by Simon Raven from Giles Cooper's 1958 radio drama "Unman, Wittering and Zigo".
 A new teacher arrives at a school and begins to suspect his predecessor was murdered by the pupils, though his suspicions are written off as paranoia.
 He sets out to prevent the same fate from befalling him.
Squadra antitruffa is a 1977 Italian crime film directed by Bruno Corbucci and starring David Hemmings, Tomas Milian and Anna Cardini.
 It is the third chapter in the Nico Giraldi film series starred by Tomas Milian.
David Hemmings Happens is the debut studio folk-pop album by former British boy soprano and actor David Hemmings released in 1967 on MGM Records, and included 9 songs.
 Hemmings once sang in his early youth with the English Opera Group before becoming an actor.
 The album was available in both mono and stereo, catalogue numbers MGM E/SE 4490.
 "David Hemmings Happens" was produced by Jim Dickson, arranged by Jimmy Bond and was recorded in Los Angeles, California.
 Guitarist Roger McGuinn, bassist Chris Hillman both of The Byrds and jazz drummer Ed Thigpen from the Oscar Peterson Trio are the session musicians for the album.
 The album has several covers: Tim Hardin's "Reason To Believe" and Bill Martin's "After The Rain".
 The songs "Good King James", "Talkin' LA", and "War's Mystery" were all co-written by David Hemmings.