Had a look just in case; no 'Cleobury' in BFI, nor 'Sindall' (of course there are results for 'Randall' and 'Thompson', but didn't establish any connections):
Sir Stephen John Cleobury s. of John Frank Cleobury (1923-2012), of Canterbury, Kent, educ. Guy's Hospital, F.R.C.P. (Edin.), deputy superintendent, St Augustine's Hospital, Chartham, consultant, Kent and Canterbury, Chaucer and Ticehurst hospitals, visiting consultant, the Maudesley 1969-, consultant, Winson Green Hospital, Birmingham 1959-69, G.P. (at Bromley -1957; formerly at St Ives), formerly physician, Bromley General Hospital, on the Parole Board, Associate of the Royal Coll. of Organists, Associate of the Royal Coll. of Music, and (m. 1947) Brenda Julie (-2011), nurse, president, Lower Hardres W.I., dau. of Frank Herbert Randall [obituary here:
https://www.pressreader.com/uk/kentish-gazette-canterbury-district/20120112/282011849227006 ; some other notices online but this gives the best account.]
J. F. Cleobury only s. [with a dau.] of Frank Harold Cleobury (1892-1980), of St Peter's Convent, Herne Bay, Kent (a care home), formerly [per his entry in 'Contemporary Authors' 1975] (see also
https://en.wikipedia.org/wiki/Frank_Harold_Cleobury and
https://www.oxfordreference.com/view/10.1093/oi/authority.20110803095617217) of 20, Desborough Close, Bengeo, Hertford, Herts., educ. Aske's Boys' Sch., Univ. of London (B.A. 1932, Ph.D 1941), Wycliffe Hall, Oxon. (for a brief time prior to his ordination), rector of Hertingfordbury, Herts. (ord. 1950) -1964, theologian, author, 'God, Man and the Absolute' (1947-), 'From Clerk to Cleric' (1976), int. al., of H.M. Commonwealth Office 1946-50 (ret. as a principal, administrative grade), formerly of H.M. Foreign Office 1911-46, M.B.E., and (m. 1922) Winifred Clara (-1949), dau. of Alfred John Sindall, of Deptford, Kent, actuarial clerk.
F. H. Cleobury s. of William Cleobury (1861-1940), of 39, Nesta Road, Deptford, Kent, brass and aluminium founder, and (m. 1887) Laura Amanda, dau. of Arthur Thompson, of Islington.
W. Cleobury s. of Thomas Cleobury (1818-1877), of Delph Side, Madeley, Broseley, Salop., 'potter' [per his probate record], 'mold maker at potteries' [1871 census], 'china potter[y] mould maker' [1871 census] and (m. 1842) Mary, dau. of John Oswell.